https://www.youtube.com/watch?v=dTWnFTjeNbc

I like his insight and hence why I am including it here. As @Bran mentions, the official leaker, he speculates they could have very well added Kitana at the end, possibly as late as November 2020 when some of the cast returned for additional filming (However, Simon or somebody also noted they had planned to go back in January 2020 or so but that was delayed and then delayed again by COVID).

To clarify, it has been noted the feudal Japan opening scene has been known, at least, as far back as a January 2019 script draft. However, the idea of feudal Japan was officially made available to the public around August or September 2019 when filming began. One of the news articles/videos about the movie's production being filmed mentioned a specific region (I; can't recall right now but my site WILL have all the articles and videos soon) serving as feudal Japan. At that time I was even thrown off by it and noted it here, because feudal Japan did not appear in either 2018 or 2016 script leak and I have yet to see a January 2019 or later draft so I can only comment on 1) what I know and 2) what I hope someone else knows who has proven reliable, lol.