The area I lived in voted for a minimum wage increase several years ago. Tons of people were saying that it was a bad idea, because the businesses would just raise prices on everything.
Minimum wage increase passed. Prices didn’t change.
I think this is because minimum wage increases don’t happen in a vacuum. There are other things to consider. If your company raises prices, I’m going to go to a competitor who doesn’t. The idea that “they’ll just raise prices” assumes that all businesses will react to a minimum wage increase in the same way, and that’s not the case.
As long as it’s a mod and not a full game, it should be fine. Typically these are distributed as patch files that don’t contain any Nintendo assets and you have to provide your own ROM and patch it yourself.
Where people get in trouble is when they try to make a full game (as opposed to a mod), like that Metroid game that was shut down awhile back.