Well I think that at least makes it clear that Beskar is bound to silence via game rules.

So for my benefit:

Beskar - Mute
Atheotes - Narcissist
DG - Cannibal
Taka - Multiple Personalities
Diana - OCD

Personally two of those just don't seem to fit. We have Diana pushing beskar for being mute and that not being something very "institute" worthy. I have to wonder about Atheotes falling in the same category.

I'm also reminded of the recent episodes of the show House, where a mute was in the same hospital as house. She had a trigger that eventually allowed her speak. There as a mental block sort of thing.

Basically I'm having a harder time believing narcissist than mute.