I never thought Scorpion was a hollow character and now he has gain something to do.
He was NEVER portrayed as this.
He has always been portrayed as a vengeful spirit, with a very interesting and well develop background, alongside Sub-Zero.
Hollow is something he never was.
The major problem with the character is that they took too long to make him realize things, and they kept binding him with Sub-Zero, instead of giving him the chance to find redemption and AT THE LEAST being neutral with Sub-Zero, who was on that time Kuai Liang.
On MK:A they also put him once again on the vengeance thing, and put him on Darkness with a (now the word is correct)hollow explanation. With MK9, they made him Quan Chi's housemaid.
I think now they are doing what should have been done in MK4, making him find peace, control.
But hollow he never was. One of the deepest character of the series, deals with a lot of themes.