My 3070 has a gpu-z date of May 2021 and I just got it from Zotac store and stock does not lay around long, the interesting part was gpu-z had no info about that card in there data bank and it has Samsung memory and it's Nov .
I was the thinking perhaps this halt was because nVidia has predicted a fallout in crypto prices some time in the near future, and they didn't want a deluge of used 3000 cards competing with new stock. However, since they can't produce enough new stock now due to demand, that logic doesn't really add up.
In summary, what they're doing here is reducing stock further so street prices go up even further. Then, when they release the 4000-series, they can bump the MSRP even higher without consumers batting an eye. It's all part of the plan: get ready for a $1000 MSRP 4080.