Oh for sure that's why I said up top this is unironically the best idea to handle the situation even though I'm not on the Grant Gustin fan train. Recasting with him in the lead following some weird multiverse/flashpoint explanation for the recasting choice would simultaneously address the criticism of Miller while also adding some good will and fan good will. He may not be ready for prime time yet...but he can probably phone in a better flash than miller at this point especially.