They are holding the 20GB 3080, 3070 etc until after the release/announcement of Big Navi in late Oct. This is just early fleecing of 2020 pigeons enamored with nVidia allure; otherwise nVidia wouldn't be rushing these out the door to be sure to snatch them up before doubt sets in. I mean, it could be the ATI/AMD of old but there isn't the old overhype part of the overhype/underdeliver paradigm in play. Its nothing but dead silence, which is a completely different move for AMD Graphics Cards.
I don't know but it sure seems like nVidia are overreacting (cut prices, paper launch, holding cards back for competitor counterpunch) if there wasn't something to fear.