Let's go back in time to April Fool's of 2017. Scott releases the following joke announcement for a movie:

“The year is 2029, and the world is a charred ruin of what it once was. The battle against the machines had raged for a decade, and humanity had almost been wiped out. But then one man, Walton, taught humanity how to fight back, and how to smash those animatronic monsters into junk. The animatronics, led by Apocalyptic Freddy, decided that there was only one way to win the war- they had to send an animatronic back in time to kill Walton's mother's cousin, because that cousin would someday befriend Walton and encourage him to lead the resistance. Apocalyptic Freddy sends himself back in time just before humans win the war. The human resistance finds the time machine however, and reprograms Apocalyptic Foxy to be Walton's protector in the past.

Now the battle for our future will be fought in our present, as Apocalyptic Foxy does battle with Apocalyptic Freddy. But not all is as it seems. Freddy is made of liquid fur, giving him the ability to turn into fur balls, and other things made of fur. Let the battle begin!”

This is all we got for them. There are no other images, mentions of these animatronics except for this description. So instead of skins, why not use this as a form of inspiration for enemies/bosses? Maybe they could be found in a radioactive area, or a torn down area of sorts? This would allow to use the imagination a bit and come up with pseudo-non-canon enemies. It's the only way I see these ever being used (maybe as bosses...?).

So... what do you think? Would you like to fight against Apocalyptic Freddy and Foxy?