Actually you will never get Ksp 2 as free update because ksp 2 is new version major number like this ksp 1 as 1.0.0 ksp2 as 2.0.0 it like new game. major is (1.⬅0.0),minor as update big things in one game the last one is Patch is Bug fixes
If major update to 2 it`s will be a new game if it update 0 to 1 it still same games. Hope i help you