I don't see the therapist saying there is a second appointment open each week as being lucky (to me, I don't see anything a therapist does from a business standpoint as being lucky to a client -clients hire them - therapists are not god on high handing down favors to the lowly clients). Here, I would see it as pressure from the therapist to conform to their idea. I would not do it the way the therapist has laid it out here and not unless I felt a strong desire to have two appointments a week from the same therapist.