we do not know, no ending was said to be Canon, i assume not because Onaga is still alive in MKA as a playable character.
we will find out 100%

Actually, we have no idea. A good amount of MKD characters take out Onaga in their endings, although it's questionable whether or not it's canon. However, the dead are rising, so Onaga's appearance in MKA doesn't mean he wasn't killed.
As for Shao Kahn's loyalty issues, doesn't every evil character in MK generally have loyalty issues? Play MK Trilogy, and every bad guy's ending has them turning on Shao Kahn. Quan Chi turns on Shinnok in MK4, the DA turn on each other in MKDA, and Tanya, Kabal, Mileena, and Baraka all betray other someone in their endings.

Actulley he didn't kill onaga yet but it said he might

Actualy in his mortal kombat Deception ending Kahn and Goro did kill Onaga. It might not be Canon but it was in Kahn's ending

Yep kahn bashed onaga with his wrath hammer into goro's poision blades. AKA - 4 Broadswords.
At the end it said all hail, Future emperor Shao kahn..
Weather it was true or not idk.
Also in goro's ending it was said that he ripped kitana from limb to limb as a token of thanx to kahn for his help in reviving him.
How ever i find this to be fake seen's in ermacs video he was currently battling warriors as they were being revived individually.
So if this was the case kitana would of never of left here friends so soon, or w/o them for that matter.

agreed i was thinking the same thing...im pretty sure goro's ending is not cannon.

Every ending leaves us thinking if its cannon or not, so we don't know until the next game rolls around. Thats how MK is

I can safely say, Goro's ending = Obsiously not canon.

Agreed

Nah because the GC version were all fake storyline.

What make's you think that?
The GC version is just as canon as any other MK game

Well, like Godzilla said. The majority of characters killed Onaga in their endings. But, many people kill people in their endings. Take for instance, Baraka, he kills Mileena. Noob-Smoke, they take down Subby. But I have been thinking for a long time, many characters, including Onaga, may have died in MK: Deception, but (this may be a lame theory) I think the Elder Gods summoned all the warriors, dead or alive and brought them to Armageddon. So many characters may have been ressurected. Including Onaga.

Most endings are not true for Mortal Kombat games. This has always been the case. What makes you think it will change now?
Shao Kahn's ending does not sound canon, and I doubt it will be. If I had to bet money on which endings will be followed I woul say Ermac's, Ashrah's and maybe Liu Kangs.

Honestly though. If this is the game that closes the book on this MK Universe, there should be a canon ending for every character. No more what if crap. Not in this game. Especially those that Boon has no intentions of bringing back. If 40 characters died, then their endings need to show them dying. None of this, "In order to prove his loyalty, Blah Blah embarked on a suicide mission to destroy blah, blah. He caught blah, blah off guard with a false show of allegence and took him out with a suprise attack. After the tournament he faded away into the shadows..." I sware to god if Boon puts an ending in there for every character possibly winning, I will find him myself and bitch slap him until my hands fall off.

casslman u said that that coudlent happen cause hes back playabul but heres mostly every oens dead the elder gods brought back every body for one last combat wtahc the thailrers dude lol

yea, I'd like to see actual cannon endings. Although just because they won't be in future games means they have to die, I do expect many deaths however.