It was Square Enix USA that chose the voices, not Japan (which of course is the authoritative instance that I always speak of when I am talking about their ideas). Just as George Newbern mentioned them. And there has not been anything said right now that they did it to still match the characters similiarly to how they were supposed to be. Aerith's voice actress is the only one so far that we know of tries to pay some sort of tribute to the former VAs.
EDIT: And if you mean SE USA also picked the former English voice cast, of course they did. But as I said before, the old VA had his own style of fitting the original Japanese vision of "majestic and inhuman Sephiroth" without just sounding like an evil human. It is not that he does not match anything at all but the "inhuman" or "superhuman" part in the (so far few) lines just was not given enough attention. That is why I said, maybe that will change once he speaks more. One can dislike George Newbern's work, just as Fox obviously did, but he at least had a style that matched the original thought to a certain extent to make Sephiroth sound "different from the basic human". The new one's work did fit a lot better than the first time we heard him when he asked "Can you bear the planet's suffering?" to say something positive about him so obviously he can "sound different".
https://www.youtube.com/watch?v=eVjwc1H7r74
That is the voice I speak of when it comes to the idea of what he is. Sean Schemmel e.g. sounds nothing like Masako Nozaawa but he still can match the "kind-hearted man-child" idea that Goku is supposed to personify. If they have this guy by the end of the day sound otherworldy than he does exactly come of as what Sephiroth is supposed to be.