In the climbing scene it is common to train finger strength by hanging from small holds. It seems to be a consensus that hanging with relaxed shoulders is considered to be dangerous and unhealthy for your shoulder both in hangboard training and in climbing rest positions.
On the other hand there is this "trend"(?) started by the surgeon John Kirsch who argues that hanging completely relaxed for some time every day will fix most shoulder problems by moving your acromion into a better position over time.
There is not really a "controversy" about those two conflicting ideas because both camps do not seem to be aware of each other at all. But it would be interesting to see some discussion on this.
Edit: To rephrase this as a question: What are the actual harms and benefits of hanging with passive shoulders both for people not yet injured and people already having shoulder injuries?
PS: My own anecdotal evidence as a rock climber with shoulder pain is that hangboard training with packed shoulders usually does not aggravate my pain while hanging relaxed from a bar seems to aggravate it at least a bit (which is the reason why i did not experiment with that a lot).