It's perfectly legal for anybody to abandon a cat they allegedly owned for years.
If there's no paper trail, of where you got the cat, or no trips to the vet for paperwork, you can move, and allegedly, leave a cat outside, to freeze and starve legally!
Dogs are different, but cats left outside are regarded as strays, with any alleged owner assumed to be a total stranger who was nice enough to let the cat inside now and then.
I learned this just a few hours ago, when I tried helping a cat that has some scary, bloody, wounds.
The cat shelter is crowded. Police have their hands tied. I have an indoor cat to worry about. All I can do is feed the abandoned cat, until it dies.
P.S. And it's now a question of abandoning a cat cause of money, since the alleged ex-owners are planning to spend money to get married. How romantic!