The rules are extremely vague which often results in cases such as this (I could find many many other examples so let's not focus too much on this one, I just picked it because it involved a popular question):
One question has over 1000 upvotes and allowed to exist
and another very similar one is downvoted and locked
I think what happens to your question depends entirely on who happens to be moderating at the time. This isn't "as defined by the community", rather, as defined by the current moderator.
We should use questions are precedents to write rules and ask anybody who locks a thread to give a reason based on these rules.