Just to point this one out here-

Let's be real, the gameplay would've been very flawed and that flaw's been already pointed out during development back in 2018/19. How would playing Music Man even work or who would have fun playing someone like Nightmare Bonnie, Funtime Foxy & so on.

A Multiplayer version of UCN wouldn't have been as good as it was initially perceived to be. Trust me, there's better multiplayer games to choose from.

The infinite Pizzeria Tycoon might perhaps be a different topic though...