I have a theory that Glamrock Foxy is the reason everyone else has the hourly recharge. My logic is "if Freddy can have an existential crisis about seeing endoskeletons, then basically anything can happen", so Foxy could get out and (because he's running on longer-lasting batteries at this point) not be found at all, just finding ways to recharge said battery when he needs to? Like a less sinister and morbid version of the Stitchwraith lol