Pretty sure its been said...
Khan is just a title, probably a way to say ruler or give some sort of huge authority.
Ghengis Khan and etc.
Shao was a name brought from Chinese origin, which would explain the commonplace use of characters like ninjas and Liu Kang and such. Likewise the idea of tournaments, the styling of legion warfare, and the focus on traditional weaponry and martial art.
Kotal does seem like a play on Quetzalcoatl, so we may be in for a more savage timeframe, a pull away from the more stylized and legion based combat and story and a focus on sheer brutality and conquest. It would make sense, should Shinnok and Quan return in this game, that a potential fellow "fallen god" who demanded sacrifice be made in his honor would team up with those who collect the dead. Its also pretty obvious that this is much later than the end of MK9, so it could also be a "someone woke up a great and ancient evil" schtick and thats the opening Shinnok and Quan were looking for. We actually don't know how Mortal Kombat occurs after MK9 because Liu Kang is gone and so is Shao, so a conquest of slowly taking victories in parts of the world would tie in decently well.
It would make sense with all the reports of things becoming more dark and brutal, and it could make a sort of timeline:
MK 1-3 -> MK9
v v
MK4 -> MKX
v v
MKDA -> ?
v
MKD
v
MKA -> ^
Now as for characters, theres a few who wouldn't exist and would exist: Reiko, Tanya, Shinnok, Quan Chi are obvious in-candidates because of their alignment, and not having any necessary connections to the now-dead cast, while Noob saibot is unlikely to return on account of I-dont-have-a-soul-itus. However, some characters like Kai wouldn't be in the game because of their necessity on Liu Kang. Jarek would be one of the few due to the survival of Sonya Blade and the death of Kano. Motaro is also seen as being killed, so is Shang Tsung. Without him, Deadly Alliance never happens. That means that Li Mei never ends up a prisoner, she never has a reason to fight in the tournament, and Bo Rai Cho never has reason to emerge since most, if not all, if his students (and future students) are dead. Fujin, should he appear, would die in the first act as Liu Kang, Kung Lao, and Kai are not around to save him from Shinnok's army.
All things considered, we are likely to see quite a few new characters, and some old ones. Goro and Kintaro are some candidates, with Kintaro being the most likely due to the more primal animalistic feel of it all. Frost is another character we may see, as it would be taking place around that time and she is unaligned. This is all speculation, of course, but it shorts up to "Characters who depend on anyone except Sonya/Cage/Raiden/The Shokan/Netherrealm/Scorp/SZ #3 probably won't be in." Characters like Ermac? Very likely, especially with Shao Khan's death. It should be interesting to see how they handle it. Overthinking concluded, time to sleep.