From what I know of Pop Warner they spend a LOT of time doing fundraisers just to get to WDW.....it certainly makes sense that they would be hard pressed to come up with an additional $50 each for a party. Plus, from what I've read about it, they are in practice/competition from early in the day until late afternoon, sometimes early evening every day they're there....so it's also hard to imagine that the coaches or whoever makes those decisions would be very happy at the thought of them being out past midnight at a party when they're supposed to be competing the next morning.
Reading past trip reports (this will be our first Nov/Dec trip so those have been great to read about what others did/saw during that time).....anyway....it sounded like the evenings saw groups of teens in the parks, but no worse than the "tour groups" that everyone complains about.....there were a LOT more people complaining about the teens behavior back at the resorts (All Stars and POR, but NOT POP), complaints ranged from loud running/talking/yelling in the walkways, even doing cheer routines outside rooms very loudly very late at night. Not sure where the chaperones are during all this, but I can say that reading all that made me change my room reservations so that we're NOT at those resorts those dates....we'll be at CBR instead. Lot of discussion about the CMs at the front desk not doing anything about the complaints either, which frankly would probably anger me more than the teenagers being so inconsiderate, after all they are teens, but the CMs ought to be reminding them to quiet down.....actually, no the chaperones should be but apparently they must have brought earplugs, and were asleep.
There is one night....I want to say it's the Wednesday, that DHS will close down early for them to have a private event.....that sounds like the biggest impact on the parks, because obviously all those that would have been at DHS will now be at one of the other 3 parks, increasing their load a bit.