MAL data is biased because he only did an all-out effort on the last 3km of the climb.
My assumption is that Evenepoel tried to replicate his 7W/kg pre-season test on a 11% climb and succeeded.
This fits with MAL Strava data on this segment:
- 0 - 1 km: MAL losing 1'06"/km on Evenepoel at 273W
- 1 - 3 km: MAL losing 12"/km on Evenepoel at 396W (6.7W/kg if 59kg)
- 3 - 4 km: MAL losing 1"/km on Evenepoel at 412W (7W/kg if 59kg)
This also fits with the data of Hindley, Reichenbach, ... Using a random web simulator and playing with the wind as a correction factor for weight/weather you get more 6.9 to 7.3 W/kg.
I think we can toss the "Evenepoel cannot cope with steep climbs" theory. Let's refocus on "bad endurance/recovery", "bad technique/positioning", or "bad preparation" theories. Or a combination of all.