I know that OP has been considering not showing up etc due to stuff related to therapy, but that's a different question from the validity of general professional policies.

Okay, I personally still cannot and would never accept that sort of style and policy for any reason. It is true though that if they make it known from start, it is up to the client to choose whether to work with that T or not. But don't think it is that simple - one might think it would be okay start, not thinking too much of it, but experiencing not being able to skip an appointment without paying can bring the harshness of that policy more upfront. I am aware that I am reacting to this topic strongly because I cringe at authority exercised in this way. Or others controlling my time in a persistent manner. I've never even had a job like that and would not. And on a job, I am paid a salary, not the other way around. Anyhow, I certainly won't change my opinion on this although I think it is very convenient for a T if they can pull it off and clients are willing to do it.