risky as a reversal, as it can be predicted and reacted to at certain spaces.
also if they attack you going low it will just go over them.
If you predict anything you can counter it. I can also attest (playing Kohaku) my 2C will only go under it at a certain time, which isn't necessairly optimal for a meaty (and if I do this, they could easily backdash out, because you can't use 2A 2C universal option select against an attack with ZERO TO ONE FRAMES activation, which is more retarded than the character itself).
22C is one of the strongest tools in the game. It has a 0~1 frame activation, and the knife goes multi-hit and fullscreen. Sure, it can be reacted to at a "certain space", and baited, but so can all wake-up reversals. Even if it has no invincibility, let's look at the different options:
1) There's really no advantage to rolling/shielding on your opponents wakeup in terms of oki with most characters, so I'll ignore that. Unless they're specifically baiting 22C, which means you're getting yomi'd so you did it way too much (like any reversal).
2) You can do a slide (like satsuki's) I believe, but it will hit you if you do 2A oki against a 22C'ing Ryougi. But why would you do that meaty? If a slide is blocked you're at mad negative.
3) You can do a sweep (like Kohaku 2C) but without the 2A 2C they can just backdash and with Ryougi's normals she can probably punish for that.
I don't want to get messy with semantics and say is it or is it not a "reversal" because it has no i-frames, but it's not a bad option on wakeup to do time to time. Honestly, it's activation punishes a 2A, any plant drop, over heads, jump ins (feint or not) and having experience fighting this matchup a lot, I can confidently say any trade with a normal almost always occurs in Ryougi's favor (short of like maybe Warc/Arc's 2B, but that also applys to situation 3 with the very possible exception of F-Warc). That's because the knife multi hit is so long that even if Ryougi gets tagged she will recover way before you can. It also has a range of other purposes for reapplying pressure and combos which I'm sure you've all gone into. This is just some stupidly godlike move.
I think it's a long shot away from a "risky reversal". It's pretty reliable. Definitely good in moderation, like CPhame said.