With California theme parks slowly reopening to in-state residents only, there are going to be some rules in effort to help stop the spread of Covid-19.
The California Attractions and Parks Association is recommending that visitors "limit activities that are know to cause increased spread" like singing, shouting, heavy breathing and raising your voice.
Which also means NO SCREAMING on rides, because moving at high speeds in different directions, with intense vocal expressions could produce droplets that could spread the virus.