No kidding.
Without "judging" him or his abilities all I need to do it look at the weather window of opportunity. If it were to be a true Yo-Yo (completing the three trails before reversing order) he'd be starting the second of the western trails no earlier than September, and would have to do that again immediately after.
Most hikers are off the PCT or CDT by October, and not about to start a Yo-Yo of even one of them.