My suggestion is to review the mechanisms of how SLAP tears occur, then compare that to kipping pull-ups and what happens in that movement. The movement where you noticed the "injury" is not necessarily the same movement that wore down the soft tissues. This pattern is very obvious in blown lumbar discs, just ask Stuart McGill.
Also, you might want to search the CF injury board under SLAP tear (or shoulder labrum tear). This injury is all too common among the CF community...my vote is that the high-rep kipping pull-ups are the culprit.
That said, do what you like.