So why the hell USUM introduced new separate Pokedex entries for Eternal Floette? Wasnt E-Floette just an unused placeholder at this point?

US: The flower it's holding can no longer be found blooming anywhere. It's also thought to contain terrifying power.
UM: Terrifying energy is concealed within its ominous flower, but Floette still swings it about innocently.

Are they still planning/considering its release?