Maybe they didn't know that Yuzuru had to go through all that to get permission. I certainly didn't and I saw someone else's comment (here? somewhere else?) that they assumed Yuzuru went through all that because he was just being respectful, not that he had to.
I’m not sure Yuzuru would’ve known to go through this process with Hisaishi on his own. I believe in the linked interview with his music editor - who actually does a lot of the editing for Japanese skaters - he had known of Kozuka’s struggles when he tried to use the music from Nausicca. I think in his case the editor had reservations about doing it and cautioned that they’d need to get Hisaishi’s blessing first. If the editor hadn’t been familiar with Kozuka’s struggle then perhaps Yuzuru would’ve had similar issues for editing the music together.