I actually think they have excluded the first MK movie from the lineup! I was browsing a MK related subreddit and they showed the 2021 movie trailer, Annihilation, and Scorpion's revenge in there, but not the original.
The hypothesis seems to be that they don't want to confuse the common audience by have a movie called "Mortal Kombat" on there right before a new movie with the exact same name, "Mortal Kombat" comes out. Could compete with the new movie, or worse, confuse some people into thinking that they're the same movie, which would be the last thing WB would want.
I do agree that having MK Annihilation on there doesn't give the franchise the best look, AND it is kind of important to see the first one to even understand Annihilation. I'm usually all for giving people the maximum amount of content, but maybe it would have been better to hold off on both live action movies until after the new one comes out.
