Not all that surprising really. The California Department of Finance (DOF), Demographic Research Unit is responsible by statute for maintaining postcensal population projections, and their report details our population projections for the state.
Before COVID the total fertility rate for California has been below the replacement level of 2.1 births per woman since 2009 and it will drop to 1.5 children per woman in 2040. COVID will probably accelerate this a little bit. Interesting stuff as it relates to future spending and income projections.