Here's the main reason I don't believe it. We know that yeast can survive in air, and in a saturated liquid that's supposed to be 8 ppm O2. We also know that when first pitched yeast will rapidly take up ALL of the available O2, and if brewers are oxygenating to 12 ppm that's 12 ppm they can remove. So hypothetically, if the yeast can drop the level to 8 ppm they're fine, thus 20 ppm should be no problem at all. And that is considerably higher than 12 ppm. Further, a healthy pitch of lager yeast (which is recommended to be twice as much as ale yeast) should be able to handle twice as much O2. So I call BS on the 12 ppm number without seeing the original data.
I suspect that the primary research will indicate some factor that will make it irrelevant for our purposes - probably that the media was continuously oxygenated, which is not what we do.