If this had been a real issue, it should have been detected quite a while ago. However as far as I can tell, this limit is reached if one is running very very quick running programs, say if it only takes 5ms to fork and run the program, then one may run into this 8 core issue.

This will basically slow down poorly written shell scripts that constantly runs subprograms - if the subprograms run in parallel (which they are not unless multiple instances of the script are running at the same time). Also it means fork bombs will create processes slower than expected on machines with more then 8 processors. I highly doubt someone would worry about this case.