The animatronics that needed reworks are Nightmare Freddy, Nightmare Mangle, Plushtrap/Nightmare BB, Molten Freddy, Withered Foxy, & Nightmare Lockjaw. I haven't figured out mechanics for Plushtrap/Nightmare BB & Molten Freddy, but for the ones I did come up with, I'll list them below.

Nightmare Freddy - You must repeatedly flash the Freddles to make them leave.

Nightmare Mangle - They can also appear at the bed. In this case, use the flashlight until their static noise fades away.

Withered Foxy - He now knocks from the Plush Hall, making the knock sounds quieter if you aren't at a plush hall.

Nightmare Lockjaw - After doing his regular attack enough times, he will groan & play hide and seek in the dark the next time he attacks. Take the batteries out of the flashlight and wait for him to appear. Then, scroll to where he is until a static noise is loud. Then, wait for him to leave.

When I figure out mechanics for Plushtrap/Nightmare BB & Molten Freddy, I'll make a follow-up post revealing those new mechanics.