Perhaps you can add an option to the game where you can toggle between the old design and the new? (For chapters 1 and 2 only of course, otherwise that would be WAY too much future workload for you). It seems like there are quite a few that became attached to the old art style and it seems a waste to throw out all of the work you've done so far as well.
Not to lie, but I would be one of those people who would be very happy to switch between either design. I love them both already even though the new ones aren't fully done yet haha!