I hope Google can pull that off, but I don’t see how it’s possible with all the carriers’ role in RCS. I wouldn’t bet on RCS ever coming into fruition, period, let alone using genuine encryption. I’d bet $10 a year from now, Google states”Forget about RCS, here is something else.”
Dieter Bohn, Composing in The Verge:
We have been hearing about RCS, the replacement for SMS texting, for

We fundamentally believe that communication
Over a year now, but actually using the next-generation service
was nearly impossible due to complex carrier and telephone manufacturer politics. But now Google is taking over: later this month,
Android users in the UK and France will have the ability to opt into RCS
Chat services supplied directly by Google rather than awaiting their provider to support it.

Is highly private and consumers have a right to privacy for their
own communications. And we are fully committed to finding a remedy for our users.

That sounds like another minor status check on the ceremony

 ★ 

Regarding RCS’s lack of end-to-end encryption, Sanaz Ahari, Google’s product management director restarting Android Messages, gave Bohn an anodyne statement:
Supposed to substitute SMS, but the truth is it is a massive shift in strategy:
since Google rolls out this offering to more countries, it must eventually indicate that RCS will come to be universally available for all
Android users.