It's likely that no-one has validated anything when it comes to future tense comparisons.
Read all, believe nothing, especially don't believe the future predictions of someone trying to sell you a laptop today.
Apple has future M1 samples for sure, but they don't have future AMD samples to benchmark against, unless somehow Apple has done some industrial espionage...
In car terms, it's like Tesla trying to persuade someone not to buy a Porsche Taycan. Of course Tesla's going to say their battery lasts longer, even longer than the second generation Taycan no-one has seen that's coming out in a few more years.