Hmm, I mean characters do come back to life and Ed did hint that the chars who died in MK9 could return. So, anything is possible, I think if anything, they should keep it a mystery as to how, what, or who resurrected Liu. If they bring him back as a spirit, it would be cool or him possessing another person. That's more along the extreme line, but don't worry about it being impossible for Liu to come back as human. They do it to almost all the chars, remember Sindel's reincarnation in the mk9 storyline?
I just hope they make it so he returns, but not as a zombie, just as a hermit, ya know? He's lost all his trust, he's cynical, just a different Liu, but not exactly evil. I don't want him siding with Kahn or like one of the sorcerers, it just is too extreme for him. His ending in MK9 is way too much for him, that's why I'm hoping it's not cannon. If it is, it won't ruin the game, but they should really just bring him back as a neutral hermit with no trust, I'm telling you.