Well remember, retrospectively for MKX hype it wasnt clear. Both Bi Han and Kuai Liang were dead and had been possessed or under the possession of Quan Chi at the end of Mortal Kombat 9: The Mortal Kombatting. And the MKX Sub Zero snippets we got didn't make it clear at the time. Because Sub and Scorp were still bitching at each other.

In theory it should be obvious from now on - Sub Zero is Kuai Liang, but that will only allow for a swerve in MK11.

So yeah, either pointlessly speculate or don't. It doesnt matter. Its all in Boon's hands now.