Whether this lock being broken will have any meaningful impact on the Nouveau developers remains to be seen
Unless something changed since it was first posted it was described as the flasher binary on Windows having a built in bypass. They used that to enable flashing anything to any card. They did not reverse engineer the signature check algorithm or actually crack it.
One dude traced the binary to the point in code execution where he found the bypass. The other dude tried to do some more complicated methods of finding the bypass and then rushed to release whatever he had because the other dude found it in one sitting.
It doesn't sound to me like this would be very helpful other than trying other signed firmware on a card.