We've spent the last few years watching carriers bungle RCS messaging, and so has Google. The search giant dropped Allo last year to focus on RCS "Chat" functionality, but the carriers have continued to drag their feet. It seems that the recent workaround to add RCS messaging on Android was leading up to something—Google is deploying RCS in the US starting today.
RCS (Rich Communication Services) is a replacement for traditional text messaging that adds features like read receipts, WiFi connectivity, larger file transfers, and more. Google helped design the standard, but the idea was that carriers could handle the deployment. As we now see, that hasn't gone well. The major US carriers recently set up a project to deploy RCS, but they're doing so without Google's backing. Now, Google is sidestepping the carriers to get RCS in the hands of the people.
A banner announcing RCS functionality will begin appearing in the Google Messages app today, but it could take a few weeks to roll out widely. Google hopes for "broad availability" by the end of the year. If you already forced RCS with the workaround, the Messages app should continue to have RCS functionality. The carriers are still working on their own RCS, the app for which will launch on devices next year. Although, even fewer people will care about that now that Google has stepped up.