That's a good point. I went back to the video to rewatch it, and turns out I totally missed where they said they only freeze things during a testing phase, then unfreeze it after they're done and allow updates to commence as normal.

They mentioned that due to Linux receiving more frequent updates often with meaningful performance improvements, they'll have to throw away older data and re-test more often on Linux, as Windows doesn't really change much in performance between updates. So I would guess that they would use release drivers with new cards, and likely would only re-test their entire suite if the release driver also gave a big performance boost on older cards.