In a type of psychotherapy called "Cognitive Behavior Therapy" opinions are offered as "hypotheses" unless there is evidence to be looked at or some conclusion is testable in some way. There can be quite a difference between a hypothesis, a working theory, an established fact and so on as you have rightly observed.

I don't know what the stardards are in other types of psychotherapy. Cognitive Behavior Therapy was developed in part by a psychiatrist was was concerned that other forms of therapy were too dogmatic and that practictioners were too authoritarian. Of course Cognitive Behavior Therapy also has its detractors.

Don't know if this information is helpful to you.