That is a very interesting idea. I would imagine it would be useful for an existing NFT holder who wants to have all its derivative assets bundled together.
However, it’s not applicable for the scenario this proposal is trying to address, which is the most common way of IP licensing. Take Disney for example, it wants to license its IP to different toy manufacturers, but won’t be any owner of such toys. Instead, all those derivative assets can have their separate owners and be traded normally in the marketplace. Disney only takes the role of collecting royalties from the trading of those derivatives.
Back to the NFT world, this proposal follows the same protocol. Derivative NFTs are not bundled to the original NFTs. They are linked instead, via interfaces defined in this proposal. And it is up to the application to define the behavior that comes with this link, usually related to royalties.