No, it hasn't. Until very recently, their website said "Buy now with 1-Click", minus the new "By placing an order, you're purchasing a content license & agreeing to Kindle's Store Terms of Use." wording underneath it. The process was identical to buying a physical book: you give them money, and you end up with your own physical or electronic copy of it.

Any interpretation of that transaction as anything but a purchase of a copy is delusional. I couldn't care less what their ToS said about it, any more than I'd care what a sign on the wall of a bookstore said.