This series has a lot of historical value to the community and has always been seen as being grandfathered in to various rules and exceptions. The following proposal is intended to formally tie up loose ends and allow the classical portions of the series to remain functional while limiting the series' scope and any potential for abuse.
Someone (ideally Isaac) post now the remaining questions through to 365.
All series posts besides 1-365 (and Purim adaptations) be deleted (or at least closed). New answers on open posts are allowed.
The tag wiki be edited to indicate the series is closed and no more questions will be accepted. Remove the tag number from the series questions to reserve it for proper site questions (like how Purim Torah doesn't get other tags).
This still leaves it as an exception to the ordinary rules of good questions, which isn't very aesthetic legally speaking, and we may have to temporarily break some ordinary rules to implement this, but it seems like a good enough compromise that has little opportunity for abuse or long term problems. Better to tweak things now and not have a bigger problem later.
I also believe this is really just formalizing what was generally seen as the expected behavior until now. It's worked fine for years, so let's make it a rule so no one can abuse the system.
If someone actually needs help finding an important fact about some other number for some reason, ask with the tag number and explain why you need that fact and how to evaluate which fact can best suit your purpose. That question will then be evaluated by all the ordinary standards (not Off Topic, not Too Broad, not Opinion Based, etc.) to see if it fits our site. It might be better to just ask in chat though.