Immortal/Defense does need some work, true. But the first change they should do is rolling back Rage/Focus to 1.3. They can keep the instant damage from Smash, that was a necessary fix. The rest was over the top. Roll it back and Vigilance/Vengeance won't seem that weak.
Immortal has been broken for a far longer time, Rage is not OP to the point where you're only seeing Sith Warriors in warzones, so I think a "fix" for the spec can wait.