Glock apparently has had a few similar issues with the slide stop wearing the slide to the point that the cut rounded off and the slide could no longer be locked back. I don't know if this was the reason they started deprecating the use of the slide stop, or if that was just added motivation to an existing philosophy.Slide releases are cheap for the Makarov but eventually I have heard this can wear down the actually cut in the slide where the release engages to hold the slide open on an empty mag.
I also don't know when these issues occurred or how many there were. Also don't know if it's still a possibility or if Glock has made changes to the design to make it less likely.