Cooscos hit the ring cancel twice if I remember correct. I play Deg fairly often who is probably a Top 10 Sonya user, for long sets and he hits the ring cancels any time he lands the low in the corner. If you're playing Sonya players who aren't capable of doing it that's another story, but shouldn't be regarded in a conversation of balance.
Who are all these "stronger than Sonya" characters though???? Geras? Erron Black LOL. I mean if all we can say is "Geras is better" that's an issue in itself no? No rational person is looking at her toolset saying it's balanced in comparison to the cast. Hell Sonic placed her at #1 in the game ahead of Geras. Reality has to hit at some point. You can't remove everything, but the insane damage, the KB damage, the best projectile in the game, the Godlike buttons and frames, SOMEthing has to give to align the Character to the rest of the game. Otherwise Combo Breaker with high representation and winning the Finals is just the start.
As far as the Wavedashing, it's MK9-esque so I'm inclined to believe it will stay. People tend to be in support of it and are applying it more and more.
I dunno man. This sounds like the Quan Chi MKX "he needs it" people, or the "MMH only has one person winning he isn't that strong" crew lol. She doesn't need to be the best at everything to compete, it just makes it easier and dumber in the context of the overall game.