The original game was supposed to be created around Jean-Claude Van Damme in a Bloodsport (1988) sort of theme. The deal didn't go through, and Van Damme starred in the movie Street Fighter (1994) based on the games of the same name. Mortal Kombat's character Johnny Cage was an "homage" to JCVD and has been one of the main characters in the canon. Now years later, JCVD is voicing Johnny Cage in this game (which will also make a JCVD skin available for Johnny Cage), coming full circle in the end. In a further bit of irony, Johnny Cage's primary voice actor, Andrew Bowen, portrayed Jean Claude Van Damme in a MadTV parody entitled "One True Impact".
John Wick was considered to be a guest character but was scrapped on account of Keanu Reeves' conflict of interest.
Raiden has taken Liu Kang's place as a Mortal in the New Era.
Liu Kang was the God of Thunder and Fire last game. However, in this game, he is just the God of Fire. It's heavily implied that the reason is because he channeled the power of his Raiden into the amulet he gave the New Era mortal Raiden.
All the character endings from Mortal Kombat 11 are canon; due to the battle for Kronika's Hourglass splintering time into various different universes.