Again, not sure. I've seen some other Abigail players say the same, and I don't particularly feel powerful in the MU or anything. But I feel like Abigail can control a lot of what Urien does, so that might be it.
Zangief is still Zangief. If he gets in, it can be lights out. Abigail has trouble against characters with command grabs, because he has no reversal defensive options. His jump is extremely slow and telegraphed, so Abby players don't want to do that too much, especially when he can get AA'd when he jumps out of the corner when an opponent whiffs a throw, if they're quick enough.
I'd say that Gief vs. Abigail is similar to MIka vs. Gief, except Abigail doesn't have an invincible command grab.
I have an easier time dealing with Birdie as Abigail than I do against Zangief. He has worse air-to-ground jump-in capability, and one of Birdie's strengthsdoing unsafe shit from good ranges that other characters can't really punishis somewhat nullified by Abby's range.