I mean, not really since you can still obtain Xmas ladder, it's just in other place, but other stuff like santa hat has been disabled. Also some small fixies has been made here and there.
Price has been reduced and currently game is on sale.
Update #9 - Price reduced, Sale and Removed Xmas stuff
Source: Steam Community (opens in a new tab)
Build and release context
Steam update times within 24 hours of this post. Matching dates do not confirm which build it describes.
Build 16999643 · public branch
Steam updated · First observed