While Google did not inform when the feature will move out of beta, the Messages app has an open beta for users who wish to sign up. This is a major milestone, though, as it brings next-gen "Chat" messaging capabilities to anyone whose carrier is a meanie and was refusing to work with Google to give them to you. I love that they're offering RCS via their app after dealing with so much headache from phone carriers - these companies generally want you to use their RCS features in their own branded messaging apps that come as bloatware on most phones and it's so frustrating.
Google will be using the Signal protocol to encrypt chats, Google's Technical Lead Manager of Communications Security, Emad Omara, said in a technical paper on the news. Here are some instructions for getting setup.
End-to-end encryption prevents anyone - even Google - from reading messages as they travel between sender and the recipient. All of your "eligible conversations" (ex: RCS used from both parties) will automatically upgrade to being end-to-end encrypted. Once end-to-end encryption is available more broadly for Android users, Google will implement it by default, according to The Verge.
"For the past few years, we've worked with the mobile industry and device makers on several carrier networks in certain countries to provide chat features in Messages based on the open Rich Communication Services (RCS) standard", Google said in a blog post. RCS messaging enables Android users to send and receive better quality photos and videos, chat over Wi-Fi or data, get read receipts, share reactions and more.