Die Hard being regarded as a Christmas movie has been growing in popularity in the culture for many years now. I did however first hear about it being discussed in a TV show, although I can't remember which.

The article also touches on another meme that has been growing for the past few years, Thanksgiving and its lack of associated songs. I remember first noticing that due to Bob's Burgers mentioning it constantly in their Thanksgiving episodes, but have now noticed that SNL has been bringing up the fact there are no Thanksgiving songs for the past couple years as well.