Don't get me wrong but I would not say that so sure. Of course it can cause problems if you don't have the PROPER TECHNIQUE down. Myself just learned after +10 years of training how to perform a pull-up correctly. It's all about the shoulders, once you're able to "pack" the shoulders there should not be any problem, if not the fact that your former PR will decrease as consequence of proper thechnique. Why? Cause it's functional approach demands more strength to execute.
Pullup problems are not always about shoulder issues. My problem is that my forearm takes on most of the stress in a pullup (and chinup), which results in serious elbow tendinitis if I do too many pullups. Consequently they do very little for my bicep size. If I try to cheat (shorten the range or kip) it only makes things worse.
I don't think it's a matter of proper form, i.e. I know how to pack the shoulder but I don't know of any way to pack the elbows.