Is AT&T planning to move towards RCS Universal Profile later?

As far as I'm aware, AT&T currently uses their own proprietary RCS client, which enables supported carrier devices to take advantage of RCS features, such as read receipts, typing indicators, and a better multimedia experience. However, in it's current implementation, it is only available for use between AT&T customers. Google announced an initiative to adopt RCS Universal Profile across all, if not most, major carriers to improve the Android messaging experience.

Is there any information, or a possibility timeline, on when Universal Profile will be coming to AT&T? Even a "coming eventually" is welcome!