I can’t speak for where you’re based, but in the UK the music videos for the singles were aired when the singles were charting and before the albums commercial release.

There is no way the anime and the movie wasn’t part of the original albums concept and neither the part you quoted nor the link I shared disagrees with that point.

I agree the album is an album of singles. But that was never in dispute.

I also deliberately avoided discussing the themes of the songs and plot of the movie but musicians are frequently reinventing meanings to songs. And if the history of operatic movies has anything to go by, it’s that musicians seldom have a coherent plot for these things (regardless of whether you’re Philip Glass or The Who) so it’s usually better to just enjoy the randomness of these movies for what it is. But that doesn’t mean that the anime wasn’t still part of the original album concept.