There is so much pent up demand I think you can almost bank on the crowds hitting whatever capacity Disney puts in place every day for the next year or so. I don’t know if the holidays will really matter.
Generally Holidays are more crowded, in the past, as more locals go to the park as well as the normal visitors.
With park passes, its hard to tell if this will hold true this year.
I agree that at least for a while, Disney can probably fill to whatever capacity limits they set.