Well, this kind of thing happens more frequently than you might imagine. Last year the same with Cocoon. Special guest advertised for closing, and then Seth had to pull out of his earlier date so they moved the booking to the closing.Since the season started it said AGORIA + SPECIAL GUEST while all other names of the guests were already known.
Now Harvey was slated to be the guest two weeks ago, but that one got cancelled due to the weather. Blue Marlin / Agoria / Drift Social media channels said Harvey would be ADDED to the closing fiesta. So that still felt like there was another special guest coming.
If Harvey is now the only guest...would be a strange story. I'm curious to see Harvey and Agoria together, cause I dont really think they match but who knows.
Could be a number of reasons - probably some financial and contractual. Or maybe they simply felt Seth - or Harvey in this case - is a bigger draw than the act they originally had in mind?