We're now in the realm of (possible) brewing mythology. "I heard this somewhere...I read this somewhere...I recall this...I recall that...from this or that brewer/homebrewer..." etc. Anecdotes passed down from "experts."
Is there credible, peer-reviewed, real-world-applicable literature on this, from actual brewing scientists, re: brewing strains of S. cerevisiae specifically? Talk to me, Dr. Bamforth.
I'll add my own anecdote: I've likely over-oxygenated quite a bit. I now even oxygenate my 1-liter starters with the O2 tank and wand. Never had an issue with yeast performance or, most importantly, the final product. But the plural of anecdote is not "data". Reactive Oxygen Species (ROS) is definitely a thing for all aerobes on this planet. But I'm not sure they have affected my beer yet.
If too much oxygen (within reason; see my previous comment) is toxic to brewing yeast, I feel like I would know by now. Could this be yet another brewing myth?