I have gone to 2 Christmas parties every year for the last 10 years and I will call baloney on this. Nobody is manning the bathrooms or snack locations. They also do not stop people from spending money in the shops.
We seldom are asked to show our wristbands other than when purchasing party merchandise and walking into an attraction. We have seen people making their "last purchases" for the evening around 9 PM who do not have wristbands. Even to the point last December where the CM told the guest they could purchase all but two of the items in their hands because they were
MVMCP items. The CM did tell them they 'should' leave the park afterwards, but there was no ushering. We went into Casey's for nachos around 8 at the 2nd party we attended and the two guys in front of us in line had no issues getting their order without their wristbands. I sat within ear shot of somebody on the bus back to the room who stayed at the party all night without a ticket. He commented on how much he enjoyed the parades and fireworks although he was unable to ride anything. :/