Dual-SIM support for RCS chats seems to be rolling out again with the latest Google Messages beta.
The feature first appeared in January this year, but Google stopped the rollout shortly after it reached a few users.
Dual-SIM support is still not widely available, but it could reach more users with a future update.
Google has been working on adding dual-SIM support for RCS chats in Google Messages for quite a while. Code related to the feature first appeared in a beta version of the app in January this year, after which the feature briefly rolled out for a few users. Google subsequently pulled the feature, but it might now be ready for rollout.
According to a recent report on Reddit (via 9to5Google), dual-SIM support for RCS chats has appeared again with the latest Google Messages beta (version 20240813_00_RC00) for a Nothing Phone 2 user in India. A screenshot of the RCS chat settings page shared by the user shows two connected SIM cards underneath the option to enable RCS chats.