As far as I know, the game is completely unchanged.

You are allowed to play on switch.

Oh really? It wasn't in the approved hardware section, but alright. Thanks!

You are also allowed to use switch for the category extensions.

is pretty much the exact same yea, beside the fact that it only can play 60 fps instead of the general 60,09x framerate of the NES, so is about 0,5 seconds slower, but is allowed

In case you missed it here's the line from the rules: Wii, Wii U, Switch and 3DS Virtual Console, GameBoy Advance

well because I think cause there is save states you know

There are savestates on every system lol

it definitely is allowed, and yea every system has savestates lol, as long as you dont use them