Apple announces that RCS support is coming to iPhone next year - 9to5Mac

Finally, Apple says it will work with the GSMA members on ways to further improve the RCS protocol. This particularly includes improving the security and encryption of RCS messages. Apple also told 9to5Mac that it will not use any sort of proprietary end-to-end encryption on top of RCS. Its focus is on improving the RCS standard itself.

Notably they will NOT use Jibe, which is Google’s RCS implementation.

Apple is going to compete against Google with trying to get carriers to use an open standard and improve that rather than going with Google’s proprietary implementation.