I think you could release the option to add someone to SyncUP regardless of whether or not they have access to the chat in question, for example, sometimes I'm on a private call with someone and I want to add a collaborator to that conversation.

Today we need to leave the call and open a new one in a shared environment.

Maybe they're looking for something more like Discord, we in the tech area love the option. Especially the part where more than one person can share a screen, just like Discord.

Another thing too, to show if the person is online but in a meeting or if they are free, such as Teams