There is absolutely no evidence to back what he says. It's would be almost impossible to prove -- since many products produced by Intel and AMD over the years were for all intents and purposes "Factory Overclocks." If what he said was true, the AMD FX 9590 would crapping out errors and bad data. His opinion has holes in it bigger than Candlestick Park.
There is no evidence that you know of. Maybe you think AMD engineers are a bunch of idiots that would leave all that performance on the table for the sake of enthusiasts pleasure. Maybe you think AMD spent tons of money validating a design for certain parameters when they could just crank up the voltage and run prime95 to validate a new bin... I can't really say what you are thinking.