Here's a basic breakdown of some stuff.
If they're airing two episodes on the first night and one after that, that places episode 93 on the 28th, the 29th if there's only one episode. Steven's Latin American VA got really emotional while recording this episode.
Assuming 26 episodes in the season, and one episode every weekday night after the first, that means that season 3 will finish on Friday, August 12th. This feels a bit early, but who knows what CN has planned exactly. Even then, the leaked episode list would put the season at over 26 episodes regardless.
I'm thinking that the scene with the CGs in the temple is Monster Reunion, and that it will be about Centipeetle.
It looks like there's an upcoming Pearl+Greg episode, which may or may not also be the musical episode from what we've seen. Although 7 songs with just Pearl, Greg, and Steven would be a bit odd.
Alone at Sea pretty much confirmed to be Lapis and Steven hanging out.
Most of these episodes are probably coming up sooner in the lineup rather than later, given CN's history of what they put in their promos.
I have a sneaking suspicion that Sugar drew this >>84251933
when the musical episode was in production.