He's definitely not stubborn. As you said, one of the more adaptable, flexible coaches I've seen at any level.I’m skeptical as well. Just saying he’s not been that stubborn.
That said, I'm skeptical for two reasons - 1) the vast majority of coaches tighten up their rotation when the schedule gets tough, and 2) Brad is known for hyperbole (i.e. he throws lots of !!!! out there).