There are so many characters that will be present in Calcenon that I wonder if the protagonist will have a chance to meet them all at the same time. However, if a big meeting between all the characters is to happen, I'll be more hyped than during the end of a certain heroic fantasy show.
Correct me if I'm wrong but I don't remember seeing any Onyx students teaming with any members of the orphans family during the whole game. Maybe this is where the branch story will come into play. Titania being present in Calcenon in one story split, we may have to follow her while the orphans are rescuing their siblings.
Also, the level cap before the next gym leader is still 90. Some mons will experiment a common candy overdose.
Also also, I'm expecting Hardy to suffer like ... a lot during this episode, if he is the gym leader of course. I can't wait to see how he interacts with his sister.