Automatically locking threads in the Bulletin Board category is normal. Immediately unlisting them, however, is not.
Their poll should have been in Development Discussion, though. That wasn’t what the Bulletin Board is for.
Edit: I’m not saying that the unlisting was an example of censorship. I mean that all threads in the Bulletin Board category are locked by default because the category is not for discussion. The reason why it was unlisted is because it was in the wrong place.