Don't forget that only the higher models are being released.At this point I'm just waiting for it to release so retailers knock another 10-15% off the Gen 3s so I can pick up one of those.
With the original Mahle version (aborted) of the gen4 there wasn't even an alloy version in development, the gen3 was to run in parallel for the lower models.
Presumably the new one will be the same, though a lot more time has since passed so they might not see the gen3 as competitive as it was.