RCS is extensible and allows for capability discovery. Adding an E2EE extension doesn't really "deviate" from the spec but rather builds on top of it. Google's

RCS is extensible and allows for capability discovery. Adding an E2EE extension doesn't really "deviate" from the spec but rather builds on top of it. Google's client can still communicate with other Universal Profile clients; the messages just aren't end-to-end encrypted. And Google has said that they plan to switch to MLS [1]. Releasing their own E2EE spec more widely at this point would be pointless. [1] https://security.googleblog.com/2023/07/an-important-step-towards-secure-and.html https://security.googleblog.com/2023/07/an-important-step-to...