OP hasn't fixed charity with Xmas festivities he's said he didn't see it. If he's suggesting end of year charities it'll work with people if they're thinking about donations. Xmas charities won't be high priority for those who don't celebrate Xmas.
OP should realize that no matter how noble they think their suggestion is, there are going to be users who won't make a head or tail out of it. They won't see reason with such a suggestion and this is because what tickles your fantasy is likely not what tickles others. Different strokes for different folks, they say. You bring in such thought, be sure to implement same during other religious festivals too, like that for the Muslims, Hindus, Krishna, Vegans etc. Otherwise, you would be accused of partiality. You see what I mean now? Just to remind you that in the recent past there were charity programmes ran by members here and the reports are documented. You could make your suggestion better by not tying it to the Xmas festivity. Those who don't celebrate Xmas won't see the need for an event tied to it. I'm one of those.
I am yet to see any post about end of year or Christmas Charity program organized by members, please correct me if I am wrong.