Today I learned Five Nights at Freddy's: Security Breach is on Switch. The game is extremely poorly optimized from what I've seen so I can't imagine how poorly it operates on the Switch, but it's neat that it's there.
I think that means just about the entire series is and will likely continue to be on Nintendo consoles, which is kind of interesting. Unfortunately the Venn diagram between FNaF fans and Smash Fans is almost two separate circles so I doubt it'll mean much for getting FNaF content in Smash, but it does at least have the Nintendo connection.