I haven't given up on the Dissidia Harmony lineup! It's just… taking longer than I thought it would… ;

As you can see, Celestia is no longer the goddess of Harmony, but you can guess what that would mean for her in the upcoming lineup! It'd make more sense. She was only a representative, a user of the elements of harmony. The tree of harmony is the essence of harmony in a concentrated form, or perhaps a/the source of it. The tree of Harmony clearly predates Celestia and Luna and perhaps even alicorns.