"the link is just the description of what they are certified to own"
No a link isn't a description of its content, just like the article demonstrated the content can change to anything, anytime, in many ways. Even if the URL contains the hash of the content like with IPFS URLs it's not a description of the content but one step better because you can check if it's pointing to the content it supposed to be.
More importantly, they don't own the original item. An unofficial version of a deed registry says they own the link to the item. That's not the same as actually transferring the copyright or anything.
No a link isn't a description of its content, just like the article demonstrated the content can change to anything, anytime, in many ways. Even if the URL contains the hash of the content like with IPFS URLs it's not a description of the content but one step better because you can check if it's pointing to the content it supposed to be.