You're definitely not getting a dodge, so, how else do you propose damage gets reduced? We already have % mitigation and shields, with Reprisal offering a debuff to the boss.
As to why we won't have a dodge, evading all damage (and by extension debuffs), is way too strong. It is also worth noting that the game will not support reactive gameplay to the point where you need to press dodge a split second before the attack comes out. Even if we look at just 'reactive' mitigation, we already have that in (most) of the short cooldowns where they have extra mitigation for the first 4 seconds.