Even Plato got some things wrong, as Porphyry knew well when he modified Plato's doctrine of the transmigration of souls (see Book X of Plato's Republic) into the more correct glorification of souls in the light of the highest possible good.
So saying "Plato never taught it" is no reason to reject the true doctrines about Jesus Christ, since they reject so central a doctrine of Plato's anyway.
Of course, the neo-Platonists likewise corrupt the good sayings of Plato, as when he discussed the creation-from-nothing (ex nihlio) of existence by God. They rather argue that we must be eternal, since we will last forever. On the contrary, Plato, reason, and Scripture all agree that there was a time when we (but not God) were not.