Ofc, Apple being Apple, I wouldn’t put it past them to artificially “break” things or arbitrarily introduce limits between RCS and iMessage
I’m guessing RCS support will be as barebones as possible while still technically functioning. All of the fancy bells and whistles will remain exclusive to iMessage.
Some iMessage features might not be possible to implement with RCS I suppose. Maybe RCS messages will get a different colour. All Apple said in the WWDC keynote was RCS would be supported, they didn’t elaborate any further.
I like containers. But they do have a habit of nurturing cludgy temporary hacks into permanent infrastructure, by sweeping all the ugly bits under the big whale-shaped rug.