I feel no need to watch any high school sports now that I am out of high school. Football, soccer, baseball, wresting, swimming, and so forth. If you (general you) do or if you want to watch your kids great but enough to cancel or move trick or treat for an entire city? Heck no.
And that is really the issue. Not whether or not you want to go watch a bunch of other people's kids play football but if that game is sooooo important that you have to arrange holidays. For a city to move trick or treat because of any sporting event, let alone a high school sporting event that shouldn't matter to anyone no longer in high school or with kids in high school, is ridiculous. No sporting event, including Manchester United, should be a reason to move trick or treat.
In our area, we have so many kids and most of them are really into sports that a Friday night football game would interfere with TOT. Even kids who aren't in high school yet go to the games/ They tail gait just like in pro football, minus the booze.
It really isn't a big mystery as to why in some areas they would move TOT. If they didn't no one would be doing it, they would rather be at the football game with everyone else in the community.
And then again, I assume you don't have kids. So it really isn't a big deal for you one way or another.
I have relatives that have to buy season tickets to their area football games and the whole town shuts down for the games, and this is all during the season, not just on Halloween.