Something new and different seems to often have issues when it first opens.
Case in point, the monster Schlitterbahn waterslide Verruckt was delayed quite a bit as they worked out issues and tested and retested.
Not that I'll have to worry about that. I wouldn't ride this thing if my life depended on it. The point is that a complicated, new attraction will have its issues and I think that most parkgoers understand that. Besides people are reporting that Diagon Alley is pretty amazing all on its own, ride or not.