Kiefer Sutherland sounds nothing like David Hayter.
Kiefer Sutherland's Snake gets his introduction shortly after, and from the get-go it's clear that this is a different Snake we're dealing with here. Previous Snake actor David Hayter's signature gravely growl is gone, replaced by Sutherland's version, which is slightly less exaggerated.
Snake's face is different too, changed to look more like Sutherland. Kojima knows that it's a big change for players, and gives Snake a suitable introduction when he pulls his night vision goggles up and says, "Kept you waiting, huh?" It remains to be seen whether fans will accept this new version of the character.