Ok, I am a lucky guy and can play MK1. So I played a few hours and Kameos are really slow and not easy to time in a combo. You almost always activate them before you start your combo, which feels anything but fluid. And some of the moves are lacking of range like Jax's airhrow (he only jumps upwards but not forward enough so in a mid air combo he can't connect). To be honest... it doesn't feel good when you fight.
Maybe some of you can play MK1 too and can confirm my concerns or deny it. But this really worries me because they need to be a lot faster to give me a good gameplay feeling.