Thousands of parents around the U.S. have made similar decisions, having their children delay or skip kindergarten because of the coronavirus pandemic. The opt outs, combined with huge declines in preschool enrollment, are raising worries about the long-term effects of so much lost early education. … Enrollment numbers have plunged in many places this fall as parents weigh health concerns and the prospect of helping young children to navigate distance learning while also holding onto their jobs.