I just got the 12 Pro Max and I was hoping they would get. I suspect that they thought combined with 5G the battery life was unacceptable. Apple often waits to perfect something before they release it so I think it'll be worth the wait.
Battery life was certainly the reason. Seems they didn’t want to do it without ltpo. Certainly were testing it without though from the sounds but ltpo was never happening this year for apple not with the amount of panels they would require