I think it probably worked yesterday too- for me it didn't pop up like an event, I had to go looking to find the store offer. There are other "red door" days coming up so we will likely have the same thing happen again.
What position did you finish in? I'm currently only getting gold if I finish in the top 3. I do not approve of thins change so I hope it's just a test.
There was no event for Day 3 of the advent calendar. Instead, it was a store offer. On Day 1 & 2 I had events appear. There are other reports of problems overall with this feature, it doesn't appear to be working for everyone.
I've had zero problems with the chocolate box, until today when it dissappeared. Unfortunately the troubleshooting advice didn't work. I will await a fix.