As you suggested, I did some research at www.tax.virginia.gov. Under “Form 760ES Vouchers and Instructions” found a recent reg that says that if any quarter’s estimated-tax payment exceeds $7,500, or within any year the aggregate payments exceed $30,000, payments must be made electronically.
So that’s a Virginia-originated excuse for TurboTax not to include the set of estimated tax vouchers—fully filled out as in the past—in its list of 2018 tax forms. BUT, it’s really a bothersome bug, which it seems to me would be easy to program around.
Incidentally, I estimate that it would take an adjusted gross income (AGI) of over $600,000 to cause Virginia’s estimated tax requirement to reach that level. What percentage of TurboTax users, doing their own taxes, mind you, have incomes that large? Everybody else is unnecessarily inconvenienced.
