The guidelines request that folks not speculate on the characteristics of others (of which mental state is one), if it hasn’t been either self-reported, or reported elsewhere.
For example, Q Shaman has been reported as being on the spectrum. Speculating about how that might have affected his behaviour is completely valid given that fact.
Our goal is not to shut down discussions about mental health! Mental health is an important topic and should not be only discussed in the dark places of the world - that’s part of the problem! But attributing shit behaviour to mental health conditions is also part of the problem and one that those who are legitimately living with mental illness have to face every time some asshole is somehow excused because “they must be nuts”.
We know that some members of QAnon do live with mental illness - we know this because several of them have been reported as having such diagnoses. That doesn’t mean they all are, as suggested by this asshat lawyer here, or more importantly, that there’s some sort of correlation because asshole, racist and bigoted behaviour and mental illness.