I've already had a work colleague suggest it is irrelevant anyway because he will stop halfway for a poo.The rule is simple, race MTB and get ranking points = better starting positions for Championships. Everybody knows this.
World Cups are different, and that rule was introduced to encourage riders from other disciplines to race MTB, and they'd get a decent grid slot. I don't recall it ever applying to Worlds.......
Since winning at Lenzerheide in August 2019, he's ridden in just two XCO World Cups....plus his ill-fated Tokyo Olympics. Plenty of opportunity to race MTB......and chosen not to.