Actually, most of wiiplayz’s uploads of those final songs were taken (aka stolen, but with the audio volume increased) from this channel:
https://youtube.com/@Daki097
This channel also has an upload of GBA Bowser’s Castle with a clean intro that was “spliced” to make the full song:
https://youtube.com/watch?si=WmKUmn49QfhRg9lf&v=-YZm6z6yhsQ
Wonder if I should tell him to ask these people instead, for the sake of having an even better soundtrack upload eventually