Per the T&C - A Cedar Fair L.P. Gold Pass is valid only at the park from which it was issued and grants a revocable license to the registered holder for admission and use of all open rides (unless restricted by conditions which could ultimately prohibit someone from riding safely, including but not limited to height, weight, age, physical limitations such as pregnancy and heart conditions, or observed inappropriate behavior), shows and attractions on any regularly-scheduled operating day of the season to the amusement park or outdoor waterpark for which it was issued.Have you ever read a contract for a park pass? I'm 99% willing to bet that there's a part in there that there's no guarantee of a certain amount of available days. A lawsuit based on "bait and switch" right now would not likely gain much traction. Somewhat like the class action lawsuits against parks for not opening in 2020 went nowhere, this would likely go nowhere.
The 2020 schedule was out at the time passes were sold. Drastically changing (I.e. not just a bad weather day) that schedule without compensation materially alters the contract signed into.