There are two problems with this:
1) It's a bad idea for a company to do something like this that so blatantly favors a specific religion's holiday due to controversy and the concept of inclusion, especially now.
2) Both implementability and practicality are virtually nonexistent. It is impossible to create such a complex idea in a day and immediately implement it. It is also unreasonable to do such a thing because its only use is on multiplayer servers, and even then has very little use due to people's desire to go off and do their own thing in these kinds of games.
I'm sorry, but this idea just wouldn't work in this sort of time frame and setting. I understand that you have a desire for easter eggs in the game (I like hidden surprises, too), but this idea is not feasible.