You really took that statement out of context...
He's talking about the long held belief of "training to take a punch"
Full quote...
He's admonishing the balls to the wall training. That you don't "toughen up" to prevent a knock out but rather focus on max recovery to do so.
Yes it was known that it existed in being "punch drunk. "
But I also think you guys are ignoring that a LOT of bro science existed/exists in training regimens in Brazil and elsewhere. Especially before the last decade. Scientific rigor and smarter evidence-based MMA training didn't really come into its own until very recently. "Training to take a punch" through chute box's infamously violent training regimens was a thing. And it's not entirely stupid on the part of Wanderlei if you don't have access to the cumulative science. You had the same focus as the NFL and others...it's the "wrong" shot or knockouts that caused it. Yes people knew you got punch drunk but plenty thought you could train your way into defense of it. And with that they took a shit load of damage training, didn't get knocked out in the fight, and then had the confirmation that their training "worked". Until CTE crept up later.
Bas can't even walk down his driveway. Gary Goodridge has CTE. Mark Coleman can barely walk after just training on his back porch with Randelman for a decade. These weren't all stupid people. The training was just in a world of, "go as hard as you can now so you'll be strong enough to not get knocked out or die in the ring".
Just look here:
New Study Finds Hits, Not Concussions, Cause CTE
Only recently with real evidence of any trauma being cumulative, not even stacking concussions or knockouts. These guys didn't have access to that knowledge and they trained with the facts they had available to try to avoid being punch drunk.