Facebook is testing a Discord-like audio channel feature for groups. There is an audio feature called Room in Facebook for groups but this audio channel feature is slightly different.
The room is for one-time audio chat, while the group members can talk to each other at any time on the audio channel. This feature is similar to Discord.
The company is also testing the feature of creating sub-groups under Facebook groups. All these features that the company is working on for the redesign will come in the app.