Sounds about right. I haven't cared for Sony since my PS3, after which I swore I'd never buy another PlayStation. First there was the whole debacle with them removing the OtherOS functionality, and then the fact they used crappy TIM which caused them to run hot and therefore loud. And when I took mine apart to try and fix it, I broke it, so I had to but a whole new one, which is when I learned they encrypt the drives to the console, so I couldn't transfer my old drive to the new system and recover all my saved games. I was just SOL, and all my progress was gone.
And it's one thing to use different suppliers, but if they really did put better fans specifically in the review units, that's a serious issue, and they need to be called out on it. This is especially pertinent as, IIRC, it was even pointed out that the PS5 is quieter than the XBOX in an article. It may be legal to use different suppliers for the same part (though I think there should be restrictions on allowed variability), but it certainly shouldn't be to do that. It's bad enough companies almost certainly cherry-pick the units they send for reviews, which is why review units should be bought off-the-shelf whenever possible, but this would be a whole other level of deceit, and a huge FU to customers.