There's a difference between injuries and a snapped neck.

Maybe his monk training allowed him to resist a broken neck by entering in some sort of catatonic state, now that would awesome writing, amirite? Seriously now, I've nothing against Kung Lao, but I'm not ashamed to say I wanted to take MK9 Storymode seriously, I thought the retcon NRS did was to create a setup for a new story in the next game, at least that's how I interpreted the good guys' deaths, definitely not for its dramatic effect, the Sindel's massacre scene was terribly executed. Kung Lao died and his soul was taken by Quan Chi, if they're going to bring him back, take it from that point, please.

Ninja Assassin, anyone?

I think the Elder gods somehow brought a few of the allies in the Netherrealm. Those who are able to escape Quan Chi's grip.

Over a few years, they went into hiding.

This time around, there was nothing unambiguous about KL actually being dead.

I too can't wait to find out how he (and any other Netherrealm returnees) feels about Raiden.

Plus, Midway already pulled that "Kung Lao may have died" nonsense back in his MK3 ending.

There is a difference between a broken neck and a snapped neck. Broken neck, you are still alive and a snapped neck, well...you die.