Now that posts can't be automatically converted to community wiki, it makes sense to just ditch all those annoying messages for "why" a post got converted in the first place. The code for selecting the message that gets displayed there has always been buggy and inaccurate. In many cases, the reason put there is not at all indicative of what actually happened.
Worse, new cases of community wiki conversion done manually still use that code. I just converted this question to community wiki, and the revision history says:
Post Made Community Wiki by being edited by more than 5 different editor
(Side note "5 different editor" instead of "...editors" is exact quote of the system message.)
Well, no, considering auto-conversion no longer exists, it doesn't even make sense to show that message on any post after that feature was removed.
It doesn't really make sense to fix this code since auto-conversion is gone. But since so many of these messages are so inaccurate, doesn't it make sense to just abandon the messages altogether? Why not ditch that code and just show the user who caused the conversion to take place in all cases?