That is not what Mayo says. The point is that if you had to draw a picture of where Evenepoel's current strengths lie, then surely it would be in rolling terrain/TT'ing and not in high mountain climbing. And who knows what the future may bring. Obviously, all Belgian fans would love a new GT-dominating rider but you should not be blinded by that hope in your evaluation of his current climbing level.
It's got nothing to do with all that. Sure i'm a fan, and while i'm excited, i'm also rather realistic. If you read through the Evenepoel topic, you'll see that both are true. I have personally described him as a mini-cancellara, who due to his tiny frame (weight), will also climb fast. I also compared him to Indurain, but a more realistic version, again due to his size/weight.
What Mayo has been saying, and he's stated that before in other topics, is that he can't understand why a 61kg kid who can pounce like he does in ITT, is still "only" at the same climbing level as Jan Polanc who is such a bad climber that he finished 11th and 14th in the Giro. But ofcourse, Mayo doesn't use Polanc as reference, but Kudus and Conti, because those fit his point better. While forgetting that he's still only 19 and probably climbing faster than Bernal at that age (going by Bernal's Tour de l'Avenir when he was 20, i'm actually quite sure of that). He also seems to forget that Remco is still not skinny as a climber, and has stated he wants to wait before working on his weight. And that he's only done his first altitude camp, a few weeks ago. While using descriptions like "outclimbed" for what is in reality a 7 second gap and Evenepoel went solo in the attack, while Kudus and Conti were cowering away in the wheel of Grossshartner. Yeah, i know what Mayo is talking about.