A while ago, even blizzard thought that mousepad's maphack was undetectable. So people did not get banned. But when Blizzard was able to determine the set of packets that were unique to maphack, without banning honest users, they patched it. Therefore: people did not get banned, but (when blizzard got their shit straight) people eventually did get banned.
And I consider revealing the map a very low yield function. There are much more useful hacks that people could be trying to discover that have less or equal risk in being banned.
Everyone always gets lured into the false sense of security by the people who code these things. I will agree, and say it may be safe...but only for now. And blizzard reps aren't going to tell you when they are able to single out users of a specific type of map hack, they'll just start compiling a list of accounts and email addresses, then ban people on some random day.