Season 6 will not have holiday episodes for some reason. That's pretty much all that there is from Comic Con.
That's not exactly what he said (I just read the transcript myself). He did say it's dependent on when they premiere. But since they're probably not going to premiere until after Christmas you're probably right that there won't be any holiday episodes.
As for Season 4, the only issue I'll have with it going in is I will always know in the back of my head that it isn't "Harmon Community." Saying that though, I hope I can enjoy it on a character level at least. I love these characters and to see them is always fun.