The bubbles should probably still be different colours (as RCS is unencrypted, so there's still a good reason to differentiate) so the vapid people who care about such things will still make a fuzz. But at least on a technical level things should work a lot better, I guess.
There's a good reason to use iMessage over SMS or RCS and making the bubble green will hide the privacy implications of using RCS. I'd rather this thing said "unencrypted" rather than RCS to be honest.
I do wonder if Apple's fallback when connectivity is limited will now also switch to RCS or if it'll still fall back to SMS. This could theoretically be a nice improvement for people in dead zones, unless they implemented RCS the Google way (hosting their own server instead of using cell carrier services).