Potential spoilers for future episodes?
New Mane 6, here we come. Most of the revelations about upcoming events in G5 more often happen on the toy front than elsewhere, we learned about Opaline’s interesting features long before this appears in MYM.
Now we know about Misty’s cutie mark, and that she is meant to play an important role; she uses electronic equipment here - and Opaline seems to be a tech skeptic. This may prove that she has freed herself from her adoptive mother. Her mane colors suggest that she had had a “magical awakening” as seen on Sunny. Then it was believed that this model is of Misty who had received her magic. Now we just need to find out what element she has.
Since the toys are coming out later in the year, that could mean that the first battle between Opaline and Sunny will happen in C4 - C5 will probably come out in the summer, way too late. Since Opaline is in the toy front, it means she will get away, no doubt as bitter as Vegeta after his defeat by Goku in the Dragon Balls. And since she has a library of spell books, it is possible that Sunny will raid her dark castle during the second battle between her and Opaline.
Sunny more and more resembles a worthy successor to Twilight. It wouldn’t be surprising if she should fall to her dark impulses if there are books that can help her ponies out.
I think C4 is coming in March, possibly at the same time or just after the conclusion of the Discord Arc. Then it is not long before the first trailer for C4, which may arrive during February.
C5 will probably be about Misty and the Mane 5, Sunny’s start of the training of her alicorn powers and the preparations for the first expedition into the world so familiar to us, yet transformed into the unknown. Won’t be surprising if Opaline shows up in C5 in a dark mood in the dark castle. Perhaps Hologram-Twilight will make her entrance in C5, revealing that Twilight is still “alive” in G5, just not available.
When C5 ends, perhaps the Wishing Star will return to witness the six cutie marks projected by the Unity crystals. Like the start of the New Mane 6. This can end S1 of G5 and start S2 of G5.