Some quick napkin math and it looks like it would be worth it to switch into deliverance (tank stance) for unchained and upheaval. Especially if the rumors about unchained double dipping on upheaval are true.
The bigger issue in my mind with this is that this would effectively mean Warrior would have 0 penalty for using a nonzero amount of tank stance, which is a huge benefit to have, essentially another 2 minute cooldown.
