I get the idea behind this. Don't go home and to sleep confused and upset for the day. But I think one could say something similar about other appointments times, eg. maybe schedule a particularly interesting and stimulating client as first of the day, or an easier case in between difficult ones. I also think that scheduling is most typically decided collectively between T and client so it's not just that the T places us wherever s/he wishes.

I always had morning time slots in therapy, my preference and I asked for it. With my last T, in one session I had the feeling that he appeared less present and connected to me than usually. I brought it up in an email afterward and he told me that my feeling was correct as he was very tired that morning since his sleep the night before had been disrupted. And that he actually became very alert during our session (there was also another client before me). He often told me that our conversations were particularly active and engaging, so I guess I can be a good wake up call