Shouldn't he be revenant for Quan Chi?
The lack of Revenant Shang Tsung, Motaro, and Jade in MKX, as well as other unknown Revenant fighters from years before, suggests to me that even Quan Chi's powers have a limit. Maintaining the enchantment must constantly drain some of Quan Chi's powers or concentration, such that he has to pick and choose if any individual warrior is deserving of the treatment.
That's all to say that Motaro is dead in a ditch under a burning bus.
Nah, he got Sindel too.
To be fair, though, Sindel's ward in EarthRealm was what prevented Shao Kahn from invading EarthRealm, so maybe Sindel was considered to be an EarthRealm warrior, even though she's not from EarthRealm???
I'm not trying to argue.
I'm just trying to provide a possible story explanation for why Sindel may have also been included as part of the "EarthRealm Kombatants" in MK9.
I may also be completely wrong on this.
IIRC, Quan Chi was given the souls of all kombatants who died in the conflict, not just Earthrealmers.
I'll have to rewatch the cutscene; I didn't think it was specific.