LOS ANGELES—Disneyland, Universal Studios and other theme parks across the state, along with outdoor ballparks and stadiums, can reopen as early as April 1 subject to counties’ rates of COVID-19 spread and with strict capacity-control mandates and required mask-wearing, state officials announced March 5. The announcement marks a major policy shift relating to theme parks, which the state had earlier said would not be permitted to reopen until their home counties reached the least-restrictive tier of the state’s “Blueprint for a Safer Economy,” a four-level system guiding reopenings of businesses and other attractions. Under the new guidance announced by the California Department of Public Health, theme parks will now be allowed to reopen when their home county reaches the “red” tier, which is the second-most-restrictive level of the economic blueprint. Los Angeles County—home to Universal Studios Hollywood and Six Flags Magic Mountain—and Orange County—home to the DisneylandResort and Knott’s Berry …