@Michael J. Caboose I don't see why not, everything to make that possible already exists. It's possible to backup and restore save games on the Switch and datamine games. Theirs already save editors for certain games out there and it's even possible to bring your Wii U save of Zelda: Breath of the Wild over to the Switch.
Why inject fakes though? similar to the Gen 3 events where we have been preserving legit event Pokemon, the same can be done for Pokemon from Go. Myself, @theSLAYER and a couple of others are already interested in putting together a living Pokedex of legit Pokemon from Go.
In later generations i'm missing a few myself too. Suicune and Entei from Gen 2 and Groudon from Gen 3. Hopefully by the time we can transfer these to future games everyone will have them thanks to research tasks though. I suspect you should be able to level theses up a lot easier on the Lets Go games too.
For regional exclusives i'm sure people on here would happily trade them with each other. I'm hoping someone form the US can trade me a unique Tauros as that's the only regional Gen 1 we've had no event for in the UK yet, it's also the last Gen 1 I need.
Either way anyone here interested in Pokemon stuff on the Switch should buy one sooner, rather than later. Every Switch out in the wild today is hackable and always will be regardless of the firmware version it's on. However Nintendo will release an updated hardware revision which patches the RCM exploit, theirs already references to this in later firmware updates, so it's just a matter of time.