Regarding you're songs, I noticed a shift in the harmonic themes exhibited from before "here comes the sun" to all the songs after the song. What I'm talking about here is how before you're year long break, the harmonies mostly consisted of like I-IV-V chords such as in "mount Saint Helens " and "when I get older" as the main chords in the verse, although they both modulate to the flat 6 at some point but those are during bridges and don't relate to the verses which is what I'm on about here. After said break the harmonies in the verses became more ambiguous, especially after "I'm scared " and in "at the corner store" where the whole of the verse is just a whole lotta Bsus4 . And in 987 where there's the maj7 slash chords and such. Might just be my imagination so point me out if I'm wrong.
i don't think your hypothesis is correct, but if it were that would be a huge coincidence because those songs were not all written in the order they were released. for example, here comes the sun was mostly written as it is now, by 2012