I've noticed that all of the winter holiday event stuff has been removed from the game and everything is back to normal except for the music. It is still playing the holiday music in Gotham and Metropolis.
This is not necessarily a bad thing, as I believe it is still fitting for the winter. Frankly, those are my favorite seasonal open world soundtracks.
Glad to see someone else enjoys the cheery tunes. Well, they're cheery in Metropolis. In Gotham, it's more dark and sinister. But still...