I’m not sure what the per park attendance is I don’t think they released that in the call. But I’d still wager the bulk of the loss is indeed at Great Adventure. That was an avoidable collapse - people have very much noticed the ride closures. That’s not necessarily an issue with the merger itself because Cedar Fair was already doing this in their own parks, but instead overzealous cost cutting with the company in general. We know Wonderland numbers are up the park itself wanted to brag on it.
The drop is probably heavily concentrated in the 2-5 US parks with the highest typical international visitor counts. Make of it what you will the 2 closest to DC saw a closure and the removal of Winterfest respectively - plus the NYC and LA coasters being pushed to 2027, those are three huge international tourist markets. And those rides plus the Carowinds water ride are rumored to be imported from Mack and Vekoma which now will have increased import costs.
Meanwhile the only newly announced ride is in Mexico, not the US, where import costs and tourism haven’t changed. That could have easily have originally been planned as another Snoopy’s Soap Box Racers. SFOT’s dive is already largely fabricated, and is fabricated in Ohio. I wouldn’t be surprised if only that, Mexico and the Canadian parks received 2026 rides.
PS: Given the current climate it’s also not surprising that IF tariffs and tourism are the reasons for the changes they’d choose to not announce that as the reason. Companies have been attacked for calling those factors out.