The current status iirc is that Google built its own e2e solutions in Android Messages, first for one-on-one conversations and as of August 2023 for group chats

The current status iirc is that Google built its own e2e solutions in Android Messages, first for one-on-one conversations and as of August 2023 for group chats as well. They released technical papers but I don't think the implementations are part of the official spec. I think this section is basically Apple saying that they are going to push for that standardization: > 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. I doubt anything has changed since 2020 in terms of China, Cuba, Iran or Russia but I couldn't find any news one way or the other