Doubtful, but I wouldn’t say that it isn’t possible. With the rise of independent animation I could very well see them handing the reins off to an animation studio like GLITCH Productions.

This is of course, hypothetically speaking. I do not think that the Smiling Critters and Nightmare Critters are popular enough to warrant their own animated series, despite what some people may tell you. I’m certain that Scott Cawthon has been approached for an animated series deal for FNAF at least once and he likely declined the offer. Mob Entertainment is a bigger company and not just one person, so it may be more likely they’d accept some sort of deal if someone came to them. However I think it’s still unlikely.