My understanding is the 100k changes files were not reviewed by a human, they did some automatic validation, so that validation could also be done on demand, e.

My understanding is the 100k changes files were not reviewed by a human, they did some automatic validation, so that validation could also be done on demand, e.g. a commit saying "reformatted" could trigger a check to make sure the files were identical and bypass a human review... but sounds like they chose a reasonable approach. I've always been against "reformat the whole code base" but it's an interesting example where it seems to have been the right choice.