I actually thought the absence of IM was a deliberate decision for Cake, from some earlier posts here on Cake. Apparently I misunderstood.
You didn't misunderstand. We were having energized internal debates about it and some of the team was expressing their concerns about what could go wrong.
My original hope was you'd be able to choose between Open, Panel, and Private conversations (although I had more confusing terms). One fear the team had was how would we make sure private conversations weren't used to plan genocides as happened on Facebook, WhatsApp and Signal.
I wasn't as worried about it as some other members of the team, I think because of my 17 years of hosting private messages on Adventure Rider. Over there, they really help help create friendships, keep threads more on topic and less noisy, ADVrider doesn't seem to be on the list of go-to apps for planning genocide.
At Cake it wasn't an urgent decision to make at the time because we had too much other engineering to complete before we could build it. But now I think we're all unified that we need to. We haven't decided what the priority is but it will probably be influenced by what we need to build, meaning how much engineering will it take?
What we need to build seems worthy of its own conversation.