Well the game is still in the very early development faze right now, who's to say that Ayami Kojima can't show up at some point down the road (once her commitments are done) and take over the artwork?
I hope that is the case, nothing wrong with this artwork but having Kojima back would just be the icing on a already delicious cake.
That's an extremely unprofessional way of handling the artwork, though. If there is another artist creating art for the game, and hell, they are in the
middle of it, they shouldn't just
replace the artist. As much as I love Ayami, if IGA let it slide and they got rid of the current artist when they've already put out pieces, I'd lose respect for IGA.