I had heard one of the lead TES creative directors left Bethesda a while back and found this reddit post: Kurt Kuhlmann Has Left Bethesda Game Studios : r/teslore - Reddit https://www.reddit.com/r/teslore/comments/17b1jw8/kurt_kuhlmann_has_left_bethesda_game_studios/

Well this seems like a bit of a blow, but the one I was actually trying to remember was Michael Kirkbride (the guy behind the CHIM stuff). Apparently he's been working as a creative consultant for them since 2000, so there's a good chance he's helping with TES VI.