If HHN had quit selling FF on September 28, 2022, maybe October 2022 would've have dropped like this year. We just don't have that data to compare. We can draw two broad trends from this year tho:
1) Most fans want the cheapest multi-night option they can buy. Probably that needs to include opening weekend so they can be "first" on social media, but we can't test that--we can only say that they don't care about October/Halloween.
2) Casual guests no longer see value in a single-night ticket. I see two possible explanations for that. Either the general public isn't as interested in this year's IPs as we thought--seems unlikely based on TV ratings--or the crowds in previous years have ruined the experience so many times guests have given up on it. It's basically a preference wave--very subtle build-up until it hits all at once.