I don't think Michigan needs elite tackle pass pro to have a great offense. Maybe my view is off, but I think they're aiming to shift to wrecking people on the ground and through the air by RPOs. Which shifts focus to the strength of the team -- Bredeson/Ruiz/Onwenu, Shea, and the WRs.
Aside from the no-huddle, loss of the fullback position, and drop in TE snaps, perhaps the next best heuristic for the extent to which Harbaugh has given over the offense to Gattis will be the percentage of pass plays that are late-developing. I'm expecting that fraction to drop by a lot. WIth it being replaced by short and intermediate stuff -- much of it likely going over the top.