According to the post, the 12-pin cable connector is only being used for testing at the moment. In other words, the supposed employee does not yet know if NVIDIA's final design will actually introduce a new PSU connector. If that ends up being the case, it raises the question of how to handle the situation on the consumer side.
There would be two main options—NVIDIA and its add-in board (AIB) partners could bundle a 12-pin adapter with their GeForce RTX 3000 series graphics cards, or PSU makers could supply the cable. The rep notes that the latter would come at an increased cost, which would presumably be passed on to consumers when purchasing a new PSU.
The folks at Tom's Hardware say they verified with their own sources that the new cable does exist. One end of the cable features a pair of male 8-pin connectors and the other end sports a 12-pin connector. It is labeled as an "NVIDIA 12-pin PCIe Molex Micro-Fit 3.0 Connector" and it measures 750mm long, according to the box pictured next to the cable. The two 8-pin connectors are designed to plug into Seasonic's modular PSUs.