GAS is essentially a raid boss
Yep. I'd noticed that too. Said it to myself in almost exactly those words.
The difference between power creep before and GAS is that damage is the single, core, unreachable mechanic without which the game loses all meaning.
While other allies exist, GAS is literally immune to health damage. Period. Until you clear all GAS' protection, all other allies are literally immune to both health damage and protection damage. They're immune to ALL DAMAGE.
Where do you go from there?
This isn't just doing a lot of damage quickly - and I agree that one character that moves quickly and does a lot of damage has been called "game breaking" by people before (Wiggs, ScavRey, etc.).
But the fact that some people have overreacted in the past does not mean that all future criticism of overpowered toons must be wrongheaded. I was wary of the damage immunity on Droideka, but there are a lot of ways that you can remove buffs and it's not immune to dispel and Droideka can't stand on its own against a full opposing squad.
This is damage immunity for an entire squad while they burn you to the ground.
Again, I have to see it in action. Maybe Anakin gets next-to-nothing for protection, so a shot or two at GAS immobilizes him and dispels the protection for a few turns. Maybe in practice it's not as bad as it sounds. We'll see.
But breaching not just A core mechanic, but THE core mechanic of damage dealing is something that seems wrongheaded to me.
I am both skeptical and displeased, and I'm not one who has complained about overpowered toons before. This really does seem to be quite different.