I did some math and came up with a conclusion about what period this game will ultimately take place in.

If Mortal Kombat 9 ended during the end of Mortal Kombat 3 you'd have to add Mortal Kombat 3's year with 25 years and you'd get 2021.

So there you have it, the latest that Mortal Kombat X will take place is in 2021.