A new homepage is a great idea, but what’s the need to change the subdomain? To be honest, forum.webflow.com sounds and looks way better than discourse.webflow.com. Also, users can still see Webflow Forum and Forum in the top bar, even though the subdomain is different. Then it would be better to change it to Webflow Discourse, no? Why not moving the homepage to discourse.webflow.com?
Anyway, not a huge deal — I think the homepage is a good starting point for newcomers. The subdomain change might be strange to some people including me.
P.S: I don’t think Discourse (the forum engine) told Webflow to change the link — it would be strange. Another conspiracy theory I can come up with is that Webflow folks are gonna launch their own forum created in Webflow. Conspiracy theory for sure lol.