Maybe each skin has a different intro?

Maybe, if the time skip thingy changes relationships (Like how Sub-Zero wasn't very happy when Cassie came to him, or how Hanzo probably talks differently than Scorpion) or just voices

Maybe kinda like dictator Superman & regular Superman

Actually i think the lines about shinnok/the revenant form is just from cut scenes of the history mode.
And in the other modes, we just use normal Liu and normal Kung.

The funny thing about Scorpion is that when he's not Hanzo Scorpion, he's pretty much revanent Scorpion which is funny because nobody refers to him as revanent Scorpion because he's you know... Scorpion lol

That said, remember that Takeda/Scorpion intro in the live stream? Surprised there isn't a thread for this yet but Scorpion says "I have returned to Quan Chi's service" which really threw me off because I was highly disappointed. But they did say that not every intro is cannon, so hopefully this is one of those which makes sense. Anyway based on that, the Revanent skins will definitely have unique intros.

I'm assuming that the Takeda/Scorpion intro has Scorpion becoming the dominant personality instead of Hanzo. The latter's mirror match further implies the two are separate entities of sorts.