It may be the end of the "character's cards are already released = character will never be released" farse. Konami may have realized that if their cards are already there, that only makes it easier to release the characters.
That's also pretty easy, not just for Lumis and Umbra. Just repeat a bunch of stuff over and over, like the ParaBros's level up rewards are the Lab Wall + equip + Shadow ad nauseum. And make just random stuff as their drops like the Bros have Neo Aqua Madoor just because he has wall on his description.