Nah look at Takeda's arms. He has full armor on his arms that guy in the tower doesn't. Also different face structure. He doesn't look like takeda.

Who knows, nothing is final, they could've changed Takeda's look and we don't know anything regarding first and alternate customes so don't get your hopes up about it being Liu Kang. The irony is that if that is in fact Liu Kang, he cannot be the final boss since he's in the tower Edit: The character people think is Jax, looks a lot more like Takeda with the robotic suit. I like the chances of this being Liu Kang more, so probably not a boss.

Mythologies was before MK1 but Shinnok killing the gods of water, earth, and fire was before MK4. In Mythologies, we are lead to believe that Sub Zero harm them not kill. This is why Fujin is still alive. Between MK3 and MK4, Shinnok waged war in the heaven and killed, Fire, Earth, and Water. That is why we don't see them in MK4.

Its too bad no leak on Liu yet.

Liu Kang's moveset surely needs more development.