There was an incident in WoL where someone modified and released the campaign maps to support co-op gameplay, from what I heard, he was asked to take down the maps. Unfortunately I cannot find any confirmation of this, although I am pretty sure there was a blue response in the thread.
I cannot say for sure, if such maps are being banned in general, but there is definitely a risk involved, especially if someone reports it.
No offense Küken, but this sounds like codswallop to me. It makes no sense. Why the hell would Blizzard release their campaign maps to the public so openly and then crack down on people who mod them? Especially after their release of Left2Die, which could easily inspire map-makers to create similar scenario's out of other campaign maps. I'm hard-pressed to believe that Blizzard will care about any of their campaign maps being modded, assuming the "Don't import HotS assets into a WoL map" rule is followed.
No offense Küken, but this sounds like codswallop to me. It makes no sense. Why the hell would Blizzard release their campaign maps to the public so openly and then crack down on people who mod them? Especially after their release of Left2Die, which could easily inspire map-makers to create similar scenario's out of other campaign maps. I'm hard-pressed to believe that Blizzard will care about any of their campaign maps being modded, assuming the "Don't import HotS assets into a WoL map" rule is followed.