GHC’s user and contributor documentation currently directs users to #ghc on irc.libera.chat for discussion of GHC development. However, for a variety of reasons the center-of-mass of discussion has been gradually shifting towards Matrix (#GHC:matrix.org).
Given that Matrix appears to be both more active and more accessible to newcomers, I suggest that we recognize this shift in our documentation. If you agree or disagree with this proposal please leave a or on #24010 and feel free to leave a comment explaining your feelings.
I believe it is the right decision, built-in persistency is extremely handy.
I am sad that bridging debacle left some sour taste between the two chatnets.
On an adjacent topic, there has been some recent discussion around the Stack project about why #stack-collaborators is on Slack (the Haskell Foundation’s ‘free’ workspace there; ‘free’ = access to 90 days of history). It is before my time, but I think the reason for Stack was a desire to work collaboratively with the Haskell Foundation. There is a discussion here about the Haskell Foundation’s choice: Reconsider Slack for HF?.
If the centre-of-mass moves, I would expect the Stack project to follow it.
or 
on #24010 and feel free to leave a comment explaining your feelings.