Would be cool. but not sure it will happen. You can just sleep the Switch if you're in the middle of a game or of course make sure the game is saved and exit it. A lot of that with emulators probably came from the fact that a lot of the older games didn't even have a save feature. Who knows though, if there's a way and enough interest maybe someone will figure it out.
Well I'm no coder or programmer by far. But from what I've read is that the emulator takes a snapshot of the registers and memory address states. So when you load the state it returns you to that exact point. It's nice when you are playing a game and don't want to keep having to load a save during difficult parts. Just wasn't sure if this was even achievable on physical hardware.