I was sad not to see a Mastodon or generic fediverse logo there at the bottom. I follow @Discourse@mastodon.social and especially with CDCK supporting the ActivityPub plugin I would have hoped to have seen it called out.
Included in my response was the fact that probably because I was an early adopter of the ActivityPub plugin on meta itself, there is something wrong in the database that causes federation not to work for me even though it works for other folks, so I can’t see meta posts on my own Mastodon account. Angus couldn’t replicate the problem on his own install, and doesn’t have database access on meta to debug the problem, so as far as I can tell I’m out of luck despite being an active promoter of Discourse on the fediverse. 
(I really wish someone at CDCK would Thanks for the fix! rails c and fix that.)