Is this because people who cancelled due to COVID in early 2020 are nearing the end of a two year extension to use any credit? Someone floated that on a FB comment and it hadn’t occurred to me.
I did notice TP’s ‘how did we do yesterday’ was way off…
Ugh… 
I may be a bit cynical at this point, but I think Disney is likely just trying to balance crowds out. If they notice an imbalance in the park reservations during busier times, block the busier parks, at least until the less busy ones catch up on reservations. It probably isn’t them truly reaching capacity except for the usual true peak attendance times. It’s just them manipulating crowd levels.
They may be doing it across days too. Trying to manipulate those with more flexible plans to shift their park vs non-park days to balance out demand.
This is probably exactly what’s going on! I didn’t realize the parks were not back to regular capacity. I just want to wake up and visit whichever dang park I want please! 