Drastic in-season changes are rare. It's just not done unless a coach's behavior toward players or other coaches crosses a line.
Highly unlikely BV makes any coaching changes until after the season. Even if Littrell were replaced, I'd expect the offense to get worse before it gets better.
You can't start installing new plays/concepts in the middle of the season and expect good results quickly.
Also, BB has been coaching offensive line blocking schemes for years, yet his line can't block anyone. I have to assume the o-linemen are just not capable.
Combined with a freshman and a sophomore qb, top 4/5 receivers injured, where would the improvement even come from?