While it's true that one wants to have the excitement of now knowing what are they going to play next, it's also a good to have a slight idea of What they are going to play.
Some people are just not masters in DT catalog and there are some songs they simply don't know (specially FII and WDADU), so, if a person who isn't very familiarized with Awake, but loves DT12 and SFAM, will be very excited for these parts during the last tour's show, but will be very confused or awkward with the Awake half.
Just a random thought.