Hiroshi Lockheimer (@lockheimer)
https://nitter.net/lockheimer/status/1667294052960849920#m
Today I'm excited to share that we're working with AT&T to accelerate adoption of the RCS standard, and that AT&T's default Android messaging will now be via the Jibe platform, so their users will get the latest RCS features instantly.
How is this different than how things are now?
It was my understanding that all AT&T had Android Messages with RCS by default
AT&T didn't use Jibe (Google), they used their own version of RCS. So when Google released new RCS features, such as iPhone reactions, Emoji reactions, replying, etc, any carrier running their own RCS implementation would have to update their RCS to add the new features Google released.
Now, every user on AT&T will be getting RCS features directly from Google, so there's no waiting on AT&T to add the new features.
Also, Googles RCS is E2E encrypted by default.
EDIT: On your phone, you can check who provides your RCS. On my Pixel it's obviously Google Jibe. 
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