On the topic of Potter being over-saturated: I think the new expansions WILL be high-quality and WILL round out the lineups of the areas, making them very worthwhile additions. However I do get the point that with SNW seeming like nothing of a distant dream right now (likely not coming until 2021 at earliest), it does feel like Uni is being overly reliant on Potter with them building two more major attractions before then. Especially after their past few non-Potter attractions (Fallon, Kong, and soon F&F) have been a bit controversial. But once SNW opens, and expansions like Zelda in Phase 1.25 and possibly Pokemon later on happen, it'll feel like less of a problem.
Plus, once Uni uses witchcraft to get the Middle-Earth rights in Park 3, it'll blow everything they've done before out of the water. Just saying...