Isn’t Apex Parks the company that was formed by ex-Six Flags executives? It’s funny how it seems to be following a similar trajectory to Six Flags. Having never been to an Apex attraction I’m not an expert, but from the little I’ve read, the closure sounds like something sudden and forced.
If you’re going to close a park down, should you give the public warning? There are arguments both ways. On one hand, you might get a rush of visitors coming for a last visit. I don't know whether they sell much merchandise/onride photos, but I can see you might well sell more if people know the park's about to close. Ethically it probably is the right thing to do. On the other hand, if staff know they’re about to lose their jobs, they might be less reliable, job hunting etc.
Nonetheless, even if you decided not to give warning before the end of the season, it’d make sense to announce the closure as soon as the park closes for the season, rather than paying a management team, engineers, maintenance workers etc to keep on doing all the normal roles they would do to prepare for the next season for three months and then announcing the closure. They’ve missed out on a rush of last visits and they’ve paid all their permanent staff to spend three months preparing the park for the 2020 season.
It also means they were still advertising season passes in January. Now they’ve announced the closure, but aren’t responding to customer asking about refunds, which you’d assume people are entitled to if the parent company hasn’t gone bankrupt/into administration. If I lived near another Apex attraction that’s still open and I heard about how the Indiana Beach season pass holders were being treated, it’d make me reluctant to buy a season pass for my local Apex attraction. I’d be worried that it too could suddenly close and I’d lose out. If you ran a chain of attractions and had decided that a few of them weren't viable and needed to close, surely this isn't how you'd go about it.