After a little digging, TechCrunch found several mentions of the feature inside Messenger's code, including a logo and a basic description: "Rooms are for public conversations about topics and interests. Each room has a link that can be shared so anyone on Messenger can join the conversation". Some TechCrunch readers were also able to launch a chat room with both friends and strangers, and an admin screen showed some sharing features that aren't available with regular group messages. For its part, Facebook offered a statement saying "We often run small tests - nothing more to share beyond that."

The original Rooms app harkened back to the good old days of open chat rooms and was something of a departure for Facebook in that it allowed users to be anonymous or use a pseudonym rather than their real name. While this rooms feature for Messenger isn't quite as full-fledged, it does offer a happy medium between the back-and-forth posting on a Group's public newsfeed and private Messenger groups -- something that might be useful as the social network looks to capitalize on messaging and chatbots.