Ability to know what users *should* be in a call, and who have historically been in a call.

### Your use case

I want to know who else has been using a given room alias (i.e. who else might barge in on a meeting)

I also want to know to know if EC is trying to connect to people and failing - i.e. who am i splitbrained with.

### Have you considered any alternatives?

_No response_

### Additional context

_No response_