Fallout 4 is an amazing game which was hugely ambitious in all the stuff you can do and see no reason why it can't come to the Switch with a few compromises. You see PC gamers making the effort to mod it to run on low level hardware. I think 2GB memory and a gpu of about 300 gflops was achieved. It looked poor but the frame rate was 20-30. I properly optimised version designed to run on weaker hardware should be possible.
The only issue is you can spend 100s of hours on that game and never complete everything, from building settlements, doing missions, following the story or just free-roaming and taking on what you find the level of content is absolutely huge. A 20 minute go on the bus or train doesn't really do much in this game world. I suppose you can always play one of the holotape games within the game.
https://www.youtube.com/watch?v=CjhJJu7a5Ic
Fallout 4 works well on remote play, Bethesda even made the effort to work well with Vita and I'm sure the Switch version while downgrading the graphics could be more responsive running natively on the Switch hardware.
https://www.youtube.com/watch?v=xWLUeN2WPYs
