I give it greater than 50% these are real. I have Chinese knockoff housings sitting around, and a new M2 housing that was in the Moto bag and came from a fire district that was getting out of the XTS game and going to Harris radios.
These look exactly like the M2 housing I have and nothing like the Chinese ones.
I have been looking all over the place for a thread that described some of the Moto factory ones that used to be sold on ebay having this issue.
Being involved in plastics in the past, I can even tell you why such a thing would probably happen - the mold has a protrusion that has to be pushed in during molding and out during removal of the finished part, and the person running the machine didn't push it back in. Or if mechanically setup, the mechanism jammed.