I think the next episode will be just a debut of Nebby, Lusamine and Aether Foundation. The episode preview from Serebii just mentioned Lusamine paying visit to the school and find Lillie, and I can see her evil look already when she hugging Lillie. It's too fast for all things to happen now, and they need time to bond with Nebby. If going by the game, they still have the third island (forgot the name) to go and Team Skull. Surprised that Guzma and Plumeria doesnt even appeared before Lusamine, oh well.
P/S: can someone point out the jigglypuff for me? I must be blind or something because I dont see it from the poster.