I would disagree. It's useful as a catch-all to include several holidays around this time. Christmas may be over, but Hanukah's still going on as is Kwanzaa, and New Year's is coming up. For those that celebrate Christmastide or the twelve days of Christmas, that's just begun as well.
Not that I'm any advocate of the disease known as political correctness, but it's a convenient, useful phrase you can start using from Thanksgiving onward to the first of the new year, as a simple, handy catch-all to include any secular and religious observations without having to constantly keep track of who's celebrating what at the moment.