I don't understand why the T should call when the person decides not to go to therapy session and not to notify? I mean, the client/patient is an adult human being and it is his own personal decision whether he goes to therapy or not and whether he notifies or not. It would be infantilising from the part of the T to start calling and asking why the person did not come.

I mean, when I have a dentist appointment or any other appointment and I cannot go then I obviously notify. Or if I forget then I don't really expect anyone to call me (and dentists and other people normally don't ever do it) and even if they would call then what would it accomplish? The only reason I can think of why they would be calling is that they want me to compensate them for not coming. And I imagine that this could perhaps be the only appropriate reason for a therapist to call too. Otherwise, adult people know themselves where they go and when and whether they notify or not and if they don't notify then for what reasons.