For the longest time Halloween night was slow because (1) people have kids who want to trick or treat and (2) if you're a singleton in your 20s or 30s, every bar in town is offering a party, usually with a high-value prize to encourage risqué costumes.
With the shift of the event toward adolescents/teens (roughly since Stranger Things arrived), Halloween night is much more crowded, with kids too old to trick or treat and too young to drink.
I've heard this went down to the wire last year, and I understand UOR's reasoning. But UFF+X alone is basically a cool half million in "free" revenue. And any change threatens to alienate the whales already upset they can't buy their way into Epic after a year. I could see the 2 pm house openings as some sort of balancing, but I'm not sure the the hard-core fans will agree.