Dude, every Corvette V8 has been all aluminum since the LS1 was introduced in the C5 in 1997. I think what you meant to discuss, was the possibility that the C7 ZR1 might get the 6.2L DOHC that was on the leaked parts/engine list from GM.
Yes, there is definitely a possibility that the DOHC could first appear in the King of the C7s. However, many feel that the C7 ZR1 needs to exceed the Hellcat HP and we know from the GM list (if genuine) that the DOHC is a normally aspirated engine and it would be a stretch to expect 750+ HP from it. The Super Charged LT4 already delivers 650 HP. The prototypes are all showing a taller bulge in the center of the hood as if a larger Super Charger might be employed to bump HP higher.
A DOHC might need a wider hood power bulge, but should not require a taller bulge.
That said, there is a reason they use Cammo on the prototypes ... to mislead guys like you and me.
That said, IF the leaked GM engine/parts list is genuine, I agree with the larger SC LT4 crowd. I think there is a very small chance that the DOHC V8 will be offered in the C7 before its debut in the C8. JMHO