Of course if they move out and the cat is still here, that means she was probably never their cat (unless they are abandoning her), and I have no idea if she belongs anywhere or not. Then I'll have to decide whether or not she's now my cat. At this point in my life it's much better to get visits from somebody else's cat than to have a cat of my own.
And if the place rents quickly and the new tenants have a dog or a cat of their own, then Black and White kitty will want to spend all her time here instead of staying next door most of the time as she's done so far. Complications. What have I gotten myself into? Why do I get the feeling I'm like the guy in this video: