Yeah, I think aeternal got woven in like other songs.
https://news.nifty.com/article/entam.../12239-731321/
Some of the Komuro / Max stuff got mentioned here. Basically he refused to make Ayu songs in 2019 because he wasn't in the mood but decided to do it for Nogizaka46 after the AKB boss was really enthusiastic so he said yes after saying no initially.