The problem with communication tools is that the meta-conversations necessary to set and adjust expectations around them don't happen as low-level and as often

The problem with communication tools is that the meta-conversations necessary to set and adjust expectations around them don't happen as low-level and as often as they ought to. So they blow up into things like the medium post. I would suggest at a bare minimum making part of the topic of your slack channels "Everyone must read everything posted here within 30 minutes," "everyone must read everything posted here on a daily basis," "don't read the history. If you didn't see it, it didn't happen" and also carefully consider everyone else's time before posting anything. I would suggest that, but I'm done getting called autistic for discussing the facets of social protocol that social protocol discourages discussing. It feels better for people to be able to speak in one of those contexts without explicitly declaring how much they want to impose on someone elses time, and nobody wants to perform out-of-band signalling as a conversation casually slips between the different contexts. The way Slack tends to get used is just a rude ways to waste other people's time.