This type of contribution is so incredibly both tone deaf and unempathetic, I wonder if you understand even how incredibly selfish the attitude is? Especially in using the word “just”. “Just” do this incredibly complex switch, which is utterly unsuitable to your users and how they work together, and which doesn’t actually solve your problem at hand since the article is about something else.
You give zero thoughts as to how the people affected are actually using the tool, why they would be in need of real time communication rather than delayed clunky messages, or even who the actual audience is.
Even with the absolute best reading of intentions I can give to your comment, I can only imagine you wrote it to make some microsubset of people still using mailing lists feel better about their choice and validated in one of the ever rarer advantages there are to using email as primary communication.
Either that or you don’t actually know what Slack is. But then why comment?