I think certain coaches deserve to be allowed down years. Sean Payton for example has some down years but seems to be able to tweak and reload.
Once a coach proves he has the right philosophy and an approach that works, I think you just let them work through it.
As long as McVay sticks with having the 3 good WRs and passes a bunch, and runs to be successful, executes the beautiful space management, and keeps the defense on their heals, versus running to punt it, I think he can stay as along as he wants.