It seems to me that the T is taking responsibility for how the T feels and knows that s/he cannot have a productive discussion. This seems to me to be a professional decision of the sort that any professional can make. S/he is acknowledging that they have some limits or flaws, or that it is a boundary for them that they will not cross (to have a discussion when they think they cannot be effective).

I wouldn't want a T to crash into a discussion that they didn't think they could handle effectively as a professional. I think I would also be upset at not getting precisely what I wanted at the time. Maybe I'd be willing to wait until after the discussion a week or whatever later to see if the T made the right call. It seems it's not over yet until then, and I could believe in the possibility that perhaps this would end up working for me.

This might just be how the T handles their business and it would be acceptable for you to decide you don't want it and see someone else. Like many things that T's do, whether it's the billing or the way the office is set up or how they schedule appointments, they are free to do business how they think is right for them. And if a client doesn't like it, you can discuss to see if it's something they can change or something you need to walk away from.

In your shoes, I might try to see it as an experiment-- as in, okay, I have to wait. Let's see if the discussion when it does happen is helpful, and consider discussing how to assess it, which of course would include the feelings of having to wait. It's not over yet and you don't have all the data to decide if this works for you or not.