It wouldn't surprise me, he IS the head of MS and the general head of the LoS project, but as far as the nitty gritty? he was very likely NOT involved. He was definitely NOT on the writing team, and that's what really matters. And it makes sense.
MoF feels like a pretty good continuation of where LoS left off, with Gabriel as Dracula. LoS2 though feels entirely disjointed from anything else.