I think the part about it that bothers me most about it being a Pity Win by design is that Ryuko's probably never comming back. DBX at most.
We joke about characters being 'fed' to the winners sometimes, but she was literally tossed into the meat grinder on that one. The episode was never 'Shadow Vs. Ryuko' it was 'Shadow finally gets a win, with special guest: Who Cares?'
Episode didn't sell me on Kill-La-Kill or Ryuko, it didn't make me like Shadow any more. It just felt like 'A Shadow win, are you happy?' paired with animation that's...fine, good in places weaker in others, But probably not going to be long-term memorable for the fanbase.
She was sacrificial lamb duty, that's bout it. Sonic fans went wild briefly and then seemed to stop caring almost immediately.
...looking at it from the meta level, just kinda sucks it had to be that way. Doesn't feel like the Sonic side got much out of it, the Kill-La-Kill fans got screwed, and casuals enjoyed it but will probably forget about it in favor of the more 'stunning' MUs.