Full disclosure, I never attended a VAH event. But going from reviews around here the general consensus was larger crowds and less of a DAH “limited access” vibe. When you have things like stage shows, Malificient walking around, etc, that pulls more people out/about in the park and it creates a different vibe.
It was really hard for me to tell from the reviews if it was in fact successful, or just a crowded paid event.
I’ve said before that I tend to underestimate Villains people (and Disney’s ability to sell Villains things to Villains people) - so I guess Disney certainly saw something they really liked in terms of being able to sell tickets to this.