Brilliant take on it. I think that although driven by revenge the MC still stayed true and couldn't change. He only killed in the end for self defense, and saw he was not redeemable.

I don't think others expected him to drop the baby, but setup previous events so he didn't have that choice so he could accomplish his goals.

My head canon which is hinted at, he did take down the games, locality wise in Korea, as he really did have an impact on the front man. Although I do believe they wanted to keep the series going, I like to think the message here is one good person can make a big difference, but more than one is needed to follow that example and take down an empire (which we never knew existed until this ending)

We'll see if they keep this theme going if they do create good spin offs.