I’ve not have any raid experience as prot warrior so far in past 2 expansions…but it seems like prot warrior issue is more in mythic+ than raid so far. Unless a significant increase - which i highly doubt so - i do not think an increase in our passive mitigation will resolve the under-represented trend of prot warrior in high end contents.
Like said, i do not know about the extra abilities of bosses in raid, hence i could be wrong about raid, but as far as Mythic+ goes, i’ve done a few as dps and see that what many said about M+ environment is legit.
It’s a headache to plan timed run around Prot Warrior with an “in-content” group (aka group that is not overgeared for the content) due to their long cooldowns. Having no bursty self heal outside of our major cooldowns means we rely on all our long cooldown cds more than say Paladin, which, ironically have more utilities and cooldown than us.
Some commented about mobility of Prot warrior, which i don’t believe is the case. While we’re not the fastest runner, we’re not lacking in mobility department as compared to say DK. Some classes like DH and BM just had advantage that’s all.
Back on the topic, to be fair, allowing us to block spells will not break the game. The conundrum of the case is that, it is not usually the spell’s damage that is key in killing us, it’s the debuff that comes with it, especially those stacking one. On the other hand, if a spell is deadly enough, even if critically blocked, it’s still can’t really match paladin’s ability to self heal when need. At least for me, i would take the ability to heal where needed as compared to blocking spell to be honest. I know we can take up Impending Victory, but it’s gonna gimp our mobility, so it’s not really useful, not to mentioned it’s only 30% as compared to Paladin’s WoG.
Perhaps the way to “evolve” prot warrior under current requirement to cope with top content, and being as fair as i can think of, would be following suggestion
(1) Impending Doom made baseline.
(2) Instead of reducing cooldown based on rage spent through Anger Management, make a talent that give us another charge of Shield Wall, Last Stand, Demoralising Shout and Shield Block. Will it be OP? i doubt.
(3) Raise the cap of Ignore Pain, i didn’t mean to go back to the OP extend of previous expansion, but perhaps increase 50% - 100% from current value would help giving us a small cooldowns that actually need to be managed.
(4) Spell Reflection can only reflect one spell during each use but will not be cancelled upon reflecting a spell.
(5) Give us one of the Deadly Calm, Enraged Regeneration or Die by the Sword.
(6) Give us one of the Howling Roar or Stormbolt as baseline.
(7) Double Time also affect Intervene.
I don’t think having ALL of the above would make prot warrior better than any tank counterparts.
Just my 2 cents.