I have a slightly different approach
Copyright is proof that a legal entity (person or company) has registered an intangible asset (creating a uniquely identifiable reference) representing copyright or intellectual property right. CopyrightShares are non-fungible assets of that CopyrightID, and Royalties tokens are fungible assets that represent dividend in the form of royalties that a CopyrightShare produces.
Since the first definition of NFT (ERC721) and more importantly when it was expanded (ERC1155) it has fitted our purpose (also as the gas price rose, it became more and more interesting).
So basically I do agree with Dani, "It's still NFT in a way".
However, we have taken it to another level and made "NFT" a visual proof of the right to receive royalties (just as old fashion Share Certificates was visual proof of receiving dividend in a company).
The first was (of course) Guy Fletcher's Fallen Angel