I have written about this before on my blog I think. (I have written so many entries by know I forget what I have actually published and what was just an idea for a post which I never wrote.) Cyberpunk as a genre really works best when predicated on the notion that it is fiction about the people who the future has left behind. That's the relentless focus of Gibson's work anyway. I think there is scope for doing the same with Shadowrun. There is now magic in the world, and elves and dragons and whatnot, so the focus is PCs as members of the measly non-magical human race, trying to make a go of it. Fundamentally though, I think Shadowrun is just kind of a naff concept. Even though I played it a lot back in the day.
As Zak rightly points out, it is all very well saying that, but it is functionally the equivalent of what Shadowrun is anyway: "the basic assumption that Shadowrun PCs are low-level mercenaries caught between massive feudal corporations". How do you actually practically make a different form of Shadowrun in which the PCs are part of an anachronistic underclass superannuated by the introduction of magic into the world? I think the broader question here is: Shadowrun is really just Cyberpunk 2020 but with Tolkien furniture all over it (an orc sofa here; an elf desk there; a dragon lava lamp in the corner). It is the ultimate high concept but the concept is only barely, let's say pathetically, followed through. It is Cyberpunk 2020 except you can be an orc and/or a magic user in it, if you want. I don't think that is really good enough.
A while ago I wrote a post about Future Maztica, following an idea I had to try to subvert the absurd, stupid and boring decision to make DM's Guild all about the Forgotten Realms. Let's use this as a starting point, because Future Maztica interests me a heck of a lot more than Shadowrun's default of orcs, elves and dragons. The basic idea of Future Maztica is fantasy Aztecs in the future. There are humans but there are also manscorpions, tabaxi, and yuan-ti, and they, being more powerful, are in charge. Because it's Shadowrun, this happened fairly recently - the world was as it was in 2016. Then it was 2017 and things changed.
What we instantly need to get away from is cybernetic implants and cyberspace. If there was magic in the world, and there were manscorpions and tabaxi and yuan-ti running the show, they wouldn't have any want or need for cybernetic implants, or for that matter the internet or railguns or e-cigarettes. They've got magic. And they come from an orthogonal plane of reality - what they are interested in is just fundamentally not what we are interested in. Social media? Those words have no meaning to a manscorpion. And their claws are rubbish on keyboards.
Rather, it is the superannuated underclass of humans in this society who are using the cybernetic implants and cyberspace. We, the underlings, are still scrabbling around with our smart phones and our laptops and our social media and our televisions - those quaint, innocent tools.
By the same token, what need have the yuan-ti for the limited liability company? What is economic profit to a tabaxi? For them, financial derivatives are little different to the conch shells which neanderthals might swap for the corpse of a deer.
My inkling is this: if Future Maztica were real, we would not understand the goals, drives, ambitions and desires of the elite which in effect ruled us. To us, these alien spirits, who use a "technology" (magic) which we simply cannot fully comprehend, whose minds are totally different to ours, and who are in all probability much more intelligent than us, would come across as being arbitrary and capricious. It wouldn't do much good to try to pre-empt their actions - we would be fundamentally reactive.
In a sense, we would be a little like the real Aztecs were when faced with the conquistadors for the first time, or like the Australian aborigines were when faced with European colonisers. There is a tale (which may be apocryphal) which tells us that the people of Central America thought that men riding on horseback were one animal on first sight - because the idea of a man riding a horse (they had never even seen horses or imagined such a thing existed) was so alien to them. Similarly, there is another (possibly also apocryphal) tale that when Australian aborigines first saw a European sailing ship they described it using their word for an evil spirit, because that was all they could really conceptualise it as. The difference, of course, is that real Aztecs and Australian aborigines were humans just like the Europeans were humans, no less intelligent, and could very quickly figure out what these interlopers were, what they wanted, and what their technology could do. But manscorpions, tabaxi and yuan-ti (at least as I think of them) are more intelligent, and not human, and do not use technology which functions on the basis of laws of physics that we know of. So we would be in a position of permanent befuddlement and mystery about precisely what these ruling classes could do; we might be able, after a fashion, to guess at motives and abilities and beliefs, but nothing more than that.
Perhaps a better analogy is animals. Think of the animals you interact with regularly - your dog, cat or budgie, or the birds you put seeds out for in the garden. Those animals don't really understand who you are or why you are doing it. They simply don't have the intelligence nor the shared assumptions. They can react to, and to an extent predict, what you are going to do - but they don't know why it is happening. I have a few bird feeders in my garden. When I put new seed in it, a few wood pigeons and collared doves are always watching. This is because they know that when I do that, it won't be long before the local flock of sparrows (who assign a lookout - I've noticed this too) come along and start to eat it, but they're so messy that the majority of the seed ends up on the lawn for the wood pigeons to scoff. None of these actors knows who I am, why I put seed out, or how I get the seed - I suppose we can ponder to what extent they understand that I am actually doing it rather than the seed spontaneously being there shortly after I have visited the feeder. But they can arrange their behaviour by watching this all unfold and learning from it. Humans in Future Maztica would be a bit like that.
So Future Maztica would be a society which is not so much divided along lines of technology and wealth, as in a cyberpunk society. Rather, it would be a society which is divided along more stark, naked grounds: knowledge, and hence power. There is an elite which rules because it is manifestly more intelligent and powerful. It has no particular interest in anything as prosaic as wealth - because that is just a means to an end, at which they are already located.
What do the PCs in such a game do, then? How does all of this depart from "the basic assumption that Shadowrun PCs are low-level mercenaries caught between massive feudal corporations"?
The touchstone, I think, is more Call of Cthulhu than Cyberpunk. The game would be more about figuring things out than it would be about stealing. What happens in a Call of Cthulhu game, if you boil it down to its essence? The PCs have all sorts of different clues about things, and discover more; gradually they tease out some tiny threads that hint at a grand tapestry underneath. They will never get the full picture because that would go against everything Lovecraft's fiction stands for. They learn a tiny bit. Then they go insane.
Future Maztica would be something like this. I picture a society in which "the 1%" are something entirely different - weird magical beings which have manifested in this world from another reality. They create a separate layer of society which exists above but also in parallel with ours - we still have our countries, our politicians, our economies and maybe even our wars, but overarching all of that is another social reality whose nature is unknowable. It all goes on somewhere else: in vast complexes behind huge walls, or underground, or on airships, or any other place that is inaccessible to the human hoi polloi. Sometimes the two different societies interface with one another, but this happens seemingly randomly or in a fashion which can't easily be predicted - like, for instance, when the manscorpions descend to order Mr Smith to give them his firstborn, or when the yuan-ti order the government of Sri Lanka to eject the Brazilian ambassador, or when human powers exercise their agency to call on the tabaxi for aid in return for some obscure task or gift.
The PCs' "job", such as it is, is to try and see behind all of this - to get a glimpse at the knowledge and power possessed by the magical elite. Their motives are akin to those of Call of Cthulhu investigators - they want knowledge for its own sake; they want power; they want information to help them; they are searching for somebody lost or taken, etc. They are not "punks" on the make. They are doing paranormal research, except that it is acknowledged fact that the paranormal exists, is fact, and exercises great power over the "real" world. They are trying to tease out some of the threads of the grand tapestry beneath. Or, to put it another way, they are pigeons trying to figure out how best to get some seeds from a bird feeder.