Lucario: Your school is not associated with gaming, and it's not directly self-supporting (in terms of visibility in the gaming realm or benefit to others) like Child's Play is. Unless we're big enough to warrant talking about on our own, like SDA is, we should just infuse the community with more goodwill. Besides that, donating to Child's Play could be good press for us.
Further, we're speedrunners, we run games with the best people available given the opportunity to. The fact that some people will be running multiple games is offset by the fact that commentary is from a lot of members of the community, some runners are quiet while focusing, some can't talk (no mic or too much background noise, etc.), and the like.
Also, running around Xmas might be fine for a short marathon, but don't forget that SDA's marathon happens in early Jan, and I'm sure I'm not the only one who wouldn't want to run into that with them.