This may be speculative guessing, yet it seems (to me at least) that Brandon the Bear and A Real Magic Skeleton tend to have a rather "intimate" friendship.
In "Plaza Prom", ARMS and Brandon take turns exchanging each other's corsage after failing to show up with dates.
In "T.K.O.", Brandon exclaims "My skeleton!" when A.R.M.S. is taken down by the bubble shield.
In "R.M.S. & Brandon's First Episode", Brandon gets shaken up when RMS decides to go looking for a solo job, Brandon is there to pick up Skeleton's bones, and they share a "friendly" hug of friendship.
Did anyone else see "Crossover Nexus"? That's where K.O. teamed up with Garnet, Ben 10, and Raven to save various other CN characters from being frozen in stone forever. It was awesome to see all the various characters new and old (as well as Ben turning into various other CN characters to deliver the final blow to the main villain), though I feel this should have been half an hour long, if only to see more team-ups. Though there is the possibility of a sequel seeing how it ended.
As a side note, it was interesting to hear that Robot Jones has his original MacinTalk voice rather than his human child voice, disproving any kind of legal issue with Apple that made the producers re-dub his dialogue.
Honestly, I'm just glad that CN actually acknowledged The Moxy Show - I thought they completely forgot about Moxy. It's an important part of CN's history because it was the first original series they aired.
And it was also nice to see Robot Jones appear. I think the last time CN ever acknowledged him was in the 20th Anniversary promo.