The evidence found that Google is working on adding a message editing feature is the existence of several new flags to the beta version of the Google Messages app. These flags were added in the beta releases that were released in the last week of November.
Currently, message editing is not a part of the RCS standard. However, Google has added features to RCS before that weren’t part of the standard, such as end-to-end encryption. It’s possible that Google will work to add message editing to the RCS standard in the future.
Apple’s recent decision to add RCS support to its iMessage application next year, could pave the way for more features like message editing to be added to the standard. This would be very convenient and a major win for users who have been waiting for these features for a long time. Currently, Apple does not plan to support Google’s flavor of RCS messaging, but rather the GSMA universal profile which does not include encryption.
Unfortunately, there’s no official word on when the message editing feature will be released to the public, but given that there are already hidden flags in the beta version of the application, this could potentially be a planned addition for a future Pixel Feature Drop. My hope is that we get to see this released in the first quarter of 2024.