The short answers are: they don't, no, and it doesn't. Some NFTs do have a separate legal document saying you get a copyright license (or maybe even the copyrig

The short answers are: they don't, no, and it doesn't. Some NFTs do have a separate legal document saying you get a copyright license (or maybe even the copyright) if you "own" the NFT, but this is not required, and is entirely separate from the NFT. The author could very easily mint multiple NFTs of the same thing or just sell more licenses of the same thing on the side; if you look into the fine print of any NFT marketplace they will say straight out that you are not actually getting any exclusive ownership of anything unless the seller explicitly says so in separate legal terms. And even then, it usually is on the buyer to do any due diligence to make sure that the copyright actually belongs to them and the artwork isn't ripped off.