Let me show you my idea on the relationship between "Her Majesty" and "Free As a Bird".
Her Majesty ends at A note without cadence.
It seems to me as if it expresses McCartney's lingering affection for the Beatles.
26 years later from then,"Free As a Bird" relased.
Amazingly, It bigins at A chord and ends at D chord.
I mean, the last A note of "Her Majesty" carries on into the first A chord of "Free As a Bird" and the last D chord which never exists on "Her Majesty" sounds at the end of "Free As a Bird".
Perhaps, rhythmic banjo on "Free As a Bird" is a echo of rhythmic guitar on "Her Majesty", i.e. paraphrase.
"Her Majesty" didn't close The Beatles, but "Free as a Bird" did.