Someone from NVIDIA might be able to add information, and I found this a difficult search. However, this is something a lot of people will want to know. This general search has some information, although not an answer:
Google search microfit3.0 power connector
It turns out DigiKey has a document about the connector family (it has different pin counts and layout details within that family):
https://www.digikey.com/htmldatasheets/production/1626160/0/0/1/0430300007.html
This one has 4 pins in a 2x2 rectangular layout. Molex has some of the same thing, although this particular connector is described as:
Lotes Co. Ltd 2 x 2 RA Female 3.0mm pitch
Maybe Molex works with this as it seems to be a standard? Don’t know. The document does make it clear though that housings are sold separately from pins, and pins may require a crimp tool specific to manufacturer.
Looking for “Microfit3.0” at DigiKey I did not find the 2x2 version. On the other hand, if clicking on the 2x2 link in that Molex document on the Microfit3.0, this turned up for the male housing:
https://www.digikey.com/en/products/detail/molex/0430250400/252497
(it didn’t look like they were in stock though)
Mouser seemed like it was useful and had a lot of variants:
https://www.mouser.com/c/connectors/headers-wire-housings/?m=Molex&number%20of%20positions=4%20Position&number%20of%20rows=2%20Row&tradename=Micro-Fit%203.0
(this filters for 4-position using 2 rows; many were in stock)
Sadly, I’m not certain of which pin would be used. We know it is a 3mm pitch, but this is not the same as “Termination Post Length” (see the Mouser URL; one filter column is on post length). I’m guessing if you dig into the details of the male housing it will suggest which pins are compatible, but this is a Molex product and I don’t know if these exactly match the same thing in the Lotes Co. version of this.
Costs are low enough you might want to order some housings and compatible pins to test with.
Can someone from NVIDIA check on the intended male part availability and pin length, or suggestions on finding the Lotes Co. version instead of Molex? Or maybe if Molex is equally compatible?
