I've had an app rejected from the selector search the article mentions. As the article says though, I'm sure it's within apple's power to ignore them, especially if lots of existing apps use it.
I believe he's saying he's had an app rejected because of a selector conflict, not specifically a selector conflict involving mogenerator.
E.g. he calls `-(void)someMethodWithTheSameNameAsAnApplePrivateMethod` in his code, and App Review rejects it because their tools are telling them he's calling a private method.