I am assuming it's a standard feature but thinking about it you might have a different set up, for example being able to turn read receipts on and off is configurable by the users job grade in our work... I suggest you try it by muting someone who's talking inane shite at the start of a meeting before its really kicked off and others are having issues joining just to see if it's working for your implementation too.
Our implementation won't show you who's muted you, again, might be something 'configurable' by the IT crowd...