Idk, ''O'' is a two part track. First is ''_______''( I forgot), and second is ''O''. And then you have part 2 of ''O''. Confused.
I guess the best way to put it would be "O" is a two movement track, while "O (Part 2/Reprise)" is a sequel. Or, for the Target edition, they took the second half of O, and put it at the end of the album, after the two added tracks.