Interesting but let’s face it, it’s just about impossible to test this scientifically. There are so many variables and you can’t blind people to the wheel size they’re riding. Luckily, it’s been proven that MTBers have no psychological bias or emotional attachment when it comes to wheel sizes.
Did you not see the part where they have covered the cyclist with sensors? They can measure the exact effort used, and a massive amount of other variables. You saying “impossible to test this scientifically” doesn’t make it so… they ARE testing it scientifically. The rider knowing which bike they are on doesn’t matter in this test, they are not just timing a loop, they are measuring effort as well, and presumably using maths and science and stuff to reach a scientific conclusion.
Now, once the results are published in full, you would be welcome to read through them and questions the results scientifically.