I certainly hope he works to bolster the line but don't see how he will influence anything regarding the style of play unless he fires the current staff and hires his own. Maybe I misunderstood...
He said his duty is "to make everyone better" and specifically talked about working to make Rivera better.
That, plus one of his primary jobs with the Giants was to scout other teams, pinpoint their strengths and weaknesses and contribute to the planning for how to beat them.
So yeah, I think he'll affect the play on the field.
Specifically, he and his staff are going to scout opponents, look at what kind of players/roster we need to beat those opponents, and act accordingly.