There’s probably musical terminology for this, but I can’t think of it.
Reminds me of the fakeout ending of King Crimson’s The Court of the Crimson King, where the song seems to end with a grand finale, but then after a few seconds of silence a tiny puppet orchestra of recorders and toy instruments comes in to play a little melody that suddenly explodes back into the full band for a second and even grander ending.
I wanted to link that moment directly on youtube, but somehow the only upload of the full song is a bizarre fan-remaster that ruins the moment I’m describing.
I think I don’t quite understand the category; is it for songs that start one way but end another way? I think your examples are continuations or extensions of the same melody, but filled out with different instruments/bravado. Does Paula’s Theme count, or is it disqualified because the two sections are so disparate? Or maybe it doesn’t count because it loops? Or is it more about the composer’s intentions rather than the technical details?
There is probably a word for this in German that specifically applies to music but I can’t think of anything right now. Intriguing question though.
There are different types of the trick. K. Rool I would call a jokey segue. Earthworm Jim would be something like a truncation to juxtaposition. Translate any of those terms to Italian and you got something fit to print on sheet music.