has clojurians ever considered moving to discord? (like reactiflux did)

Many individuals have asked. There was no official decision making body that made individuals choose to use Slack as often as they do, and nothing stopping anyone from choosing Discord only, Discord and Slack both, etc

If one wanted to publish a link to the Discord channel on the Clojurians Slack #announcements channel, say no more than 4 to 5 times per year, to let people know that it exists, I doubt that would be out of line, but please not more than that.

There is an active Discord Clojure community but it's pretty small. I believe it (and several other small Clojure communities) are all linked from the Clojure sub-Reddit?

This sort of thing is discussed from time to time in #community-development