Yes and no. `gofmt` is a tool to make your code follow certain style guidelines, and the ordering of imports is part of those guidelines. You are always free to ignore the guidelines, but then don't complain about the tool which is created to enforce them.
It is also incorrect to rely on the order of import initialization at all, because it's undefined, implementation specific and may change.
So it sounds like... yes and yes. Guidelines are guidelines. If they are more than guidelines they must be enforced at the language level.
Undefined behavior is another thing. Surely, it's poor form to rely on undefined behavior. However, that doesn't mean it isn't possible for such a situation to arise. An accurate description of how that can happen doesn't deserve a downvote.
On the contrary, it's quite valuable for a newbie (like myself) to learn the facts, not just the dogma. Downvoting an accurate description of the behavior of the tool because you think the situation shouldn't arise in the first place is simply a misplaced use of a downvote.
It is also incorrect to rely on the order of import initialization at all, because it's undefined, implementation specific and may change.