Cedar Point has a different announcement, basically just like Carowinds's current announcement and dated the same day, 3/20, in the form of a release by Zimmerman:https://www.cedarpoint.com/park-update
"For 2020 Season Passholders, we will be adding days to the park’s operating calendar to accommodate for the days the park is temporarily closed (against original 2020 operating calendar). Additionally, 2020 Season Passholders will enjoy added-value benefits to be announced at time of park opening."
I wouldn't be surprised if this changes later to match Knott's. It's good business and keeps customer satisfaction and expectation high, even though it will hurt base revenue obviously.