I agree!
When the Chanukah song came up, I thoght, "what the...????!!!! heck was that doing there?!"
Candlelight Processional is the telling of the Christmas story. Chanukah is not in any way part of Christmas or the Christmas story!
It's such a touchy subject. I'm sure that Disney in their own way was just trying to keep everyone happy and involved in some way. Or all-inclusive, as I've heard it said.
When it comes to religion and theme parks, you just know there's gonna be some upset people somewhere along the line. Either the Christmas theme is 'too religious' or 'not religious enough' or 'not the right religion' or 'my religion wasn't included'. There's no way to win in those situations sometimes.
I'm definitely not saying people shouldn't be upset or irritated or comment about it . I understand completely

I guess I'm just saying that no matter what the scenario, there will always be an upset party whatever the case may be. I guess that's just the way things are
I myself am not religious. However, I've never been upset or offended at Christmas decorations of any sort. Same goes for Hannukah or Kwanzaa or Solstice or whatever have you. When push comes to shove it's about tolerance. Sure a Hannukah song in the middle of a Christmas story is out of place, and might have been ill-fitted for the occassion. Yet, at the same time, I'm sure there were people in attendance who were happy to hear a mention of it. Bottom line is you're not at a church. Don't expect it to be the same.
I suppose I'm not too sure if I'm trying to make any sort of point. Maybe if you're so religious that every little thing you don't agree with ruffles your feathers, the parks during the holidays isn't the best place for you. Christmas is a huge holiday no matter where you go, and especially for Disney.
Go in knowing what to expect. A whole lotta winter theming and a touch of other cultures here and there. Fully grown adults going into WDW in December and being irritated at decorations just makes me roll my eyes. Be it Christmas or Halloween or Valentine's Day.
Do your homework.