It's not to say that Johnny would have been the central hero of the story if he were part of the lineup this time around (he hasn't been officially disconfirmed yet, but the writing does seem to be on the wall), but Garner does note that he really wouldn't want Cage, being a white male actor, to be the central focus.
"I feel like if I was getting to make a movie with a diverse cast, it felt weird to have a white actor, literally Johnny Cage, be the hero of the story," he states.
The film's current lineup does indeed boast a diverse cast, and many associated with the project, including Garner, have highlighted this fact as one of their biggest overall successes.
https://www.eventhubs.com/news/2021/mar/18/mortal-kombat-producer-johnny-cage/
Aw man, Mortal Kombat was such a great game series. I was just fun to play, and I used to play as Johnny Cage. But I never thought of him as the central character, not even in the movies. Nor did I really notice what race or whatever each character was. They were just pretty cool characters. And a lot of them wear masks so you don't know what they are.
This saddens me that something else I used to like a lot has gone "woke".