Why didn't TurboTax know that my state was going to flag me for proving my identity

TurboTax never knows such things.  TurboTax provides the software for you to use for a do-it-yourself tax return.  The state does not tell TurboTax anything whatsoever about your tax return after you file it.  Many states (and the IRS) take extra measures to prevent fraud and identity theft.  Some returns are chosen randomly, and some are chosen due to something that does not look right to them.  No one at TurboTax knows why your return was chosen for identity verification.  If you need to provide information to the state to get your refund, then provide them with the information they are requesting as soon as you can, so that you can get the refund.