My guess is a couple of things:
-
its an entry level vo2 session (3.5) so the long rests are to get people to get through it when not really used to vo2 work (rather than drop the power and not really complete much time in the right zone)
-
probably more likely is TR know exactly how many people actually complete vo2 sessions with shorter rest periods, and realise that not many actually do…so long rests means higher completion rates
But they really are loooooong rests so it seems a little bizarre to me…