Let's see--grandson is having a Holiday Party on the 16th of December, the children are exchanging Holiday gifts on the 23rd. They're making a Holiday Gingerbread House. Haven't heard a word about a concert of any kind so far this year.
Last year, they had a concert (2nd grade) with holiday songs--Kwaanza and Hanukah songs were sung and, I guess if you consider Rudolph the Red Nosed Reindeer to be a Christmas song, then it was included.
In his class he learned all about Hanukah and Kwaanza. I think I still have the projects he worked on for those topics. Christmas was not included. Wasn't even mentioned.
So, yes. We have seen it in Connecticut. At least in this part of Connecticut.