In addition, he clearly lost the endurance he had last years, as we could see in E3 and Flanders. Last year, he would get to Terpstra and Lampaert I think, and he would not run out of steam after the patterberg in Flanders. As I believe the endurance came with increased weight, and for Insbruck he needs to be lighter. And as you stated, he still was not ready to fully sacrifice the spring, he only lost something pre spring and will continue to loose weight during the year.
For me, the arguments start to add up. However, I do think that it's stupid idea and he shouldn't do it.
For me, that argument falls apart where he’s losing the endurance for a 260km Ronde van Vlaanderen to prepare for a 260km WCRR.
I could understand if he was losing weight to get up the longer climbs in Innsbruck, so was suffering over the shorter more explosive climbs in Flanders. But he dropped everyone on the explosive climb up the Paterberg, and then didn’t have the speed over the following flat kilometers.
I’ve always thought he has the ability, if he drops a few kgs, to win any/every race on the calendar, if he wants to. But I don’t think he’s started that just yet.