Well, I was planning on having that map just sort of being the only canon map in the set.
However, if the level is just a regular level featuring the new Peter Hitler boss, then I'm all for it, as that's what I was going to put there.
Otherwise, as I said these were non-sequitors (unless it's a gripe about the music, in which case you can just have the music on another one fo the levels replaced for that tune. Sure it'll add to the overall size fo the set, but I figured that'd just have to happen in that circumstance).
But it doesn't matter which slot your map is in. I personally expect them to be erratic in style, quality and difficulty. That's just how community mapsets are.