Don't panic. Just backup your install, and nobody can take it away from you.

When you buy a video game, it's like buying a piece of art. You still want to be able to go back and enjoy it in 80 years right? So don't leave it in a vulnerable state. Back it up, disable all updates, put it in a VM if you have to. I go back and play my modded out 0.17 install every now and then because it was good. And it's still going to be good when I'm an old man, nomatter who owns KSP or if the whole game industry gets as boring as Hollywood in the meantime.

So don't panic, just back up your install and enjoy what you got.