This presents a tactical opportunity for the opposition to push in the scrum and win the ball, or at least disrupt the feeding/attacking side.
There is no law of "uncontested scrums" in RL, it is simply how tactics have developed - primarily driven by the conservation of energy as the feed has been allowed to move back to the second row.
Forcing the feed back in the middle of the scrum would just mean teams started pushing again - and still the feeding team would win the ball almost every time as they would cancel each other out, just at a greater energy cost.
This scenario might lead to a change in forwards' skill sets towards pushing and heaving, and away from smashing the ball up and smashing the ball carrier.
As a spectator I would not welcome this as I much prefer the smashing to the heaving!