Phylloxera on the leafs of American vines will not kill the vines. It looks ugly, but the vines should survive. Phylloxera is a death sentence to European vines, not from leaf damage, but from the root form of phylloxera which will kill the vines by killing the roots. Meanwhile, I have never seen any leaf phylloxera damage to my European vines.
I actually grow American vines for root stock, for grafting, and they often have significant phylloxera leaf damage. But the vines do fine, never had one die. In fact, they are quite vigorous and healthy. They long ago adapted to phylloxera. Hybrids should perform somewhere in between. But since the main issue is phylloxera on the roots, which most hybrids address rather well., I would not worry too much about phylloxera on the leafs.