The use of autumnal leaves as a metaphor for a change in circumstances is not uncommon in popular music. Here are a three more examples:
"Autumn Leaves Revisited
" by Thursday (About a child who loses their father in a war).
" (This jazz standard about lost love and regret has been recorded by many artists, including Nat King Cole, Frank Sinatra and Steve Allen).
" by Susan Boyle (About losing someone you love).
And here's three more about the last leaf of autumn representing persistence:
" by OK Go (Waiting on a girl, even if she turns out to be the last leaf hanging on a tree)
" by Chris Brown (About working hard for a difficult relationship and holding on like the last leaf of autumn).
" by Tom Waits (Reflects on how he's managed to stay alive for so long, when so many of his contemporaries have fallen to the ground).