Do they do away with the grounding rule?

In the continued interest of keeping QBs safe will there eventually be a change in the grounding rules?

If Tua doesn't have to roll outside of the tackle box does he just stay in the box and throw away?
(I dont think that was his thought process, I think he was attempting to extend the play)
Just kinda had me thinking why would you even have "out of the tackle box" a part of the rule. Would it make a difference if that part was taken out?