For me the much scarier weaponization is to change the linked content to be something illegal after you buy the NFT. How would you prove the illegal thing is not the thing you bought? (You will certainly not be treated as innocent until proven guilty if we're talking child pornography in the USA or democracy advocacy in China, etc etc.)
I don't think making them revocable defeats the purpose, it's having the registry of NFTs effectively being "OpenSea API" and not "blockchain" that's the problem. Having the NFT content itself be erasable is probably a good thing as long as there is some way of making a local copy. Sometimes we want the government to have the ability to stop the spread of information; but (subject to the risk of your possessing it) your "ownership" of content with a hashed URL is also going to apply to the download, assuming the hash is reproducible.
It's possible to place illegal content onto the Bitcoin blockchain.
I wonder if Bitcoin already has illegal content in it.
But you're solution is bad, that's why no one does it. A much better solution is to use a decentralized file hosting protocol and store your base NFT file on it. These protocols are free to prune illegal data should their government force them to, but are economically motivated not to. With enough redundancy, (and if you're NFT is so valuable you'll keep a local copy) this isn't a problem.
And the second argument is that country can still censor (to an extent)
An issue with general-purpose immutable storage is that it can be permanently polluted with illegal data. Everything from child pornography, instructions for making drugs or explosives, doxing/attack information, private keys for copy protection systems, etc...
It would be possible to make Ethereum or any similar blockchain illegal to the level of "penalty of death" in many countries by simply adding some horrendously blasphemous text content to it.
Even if bulk image or video data is too expensive to store, an option would be to simply use torrent "magnet:" links.
Bitcoin is just for financial transactions, so I doubt it would be vulnerable to this, but the more generic chains don't seem to have any way to protect themselves from this kind of attack.
Seriously, what would happen if a bunch of paedophiles started minting NFTs of their favourite child pornography and trading it? They would be "protected" by the inertia of the block chain. Governments eventually would have to step in and make it totally illegal, and then.. that's it. The value would instantly go to zero!
Alternatively, NFTs would have to be made revocable or erasable in some way, but that then totally defeats the purpose. That's the author's point -- his dynamically changing NFT was revoked in this manner.
I just don't see a way around this. Either you allow indelible illegal content, or allow forced revocation. Either way, the value of NFTs must go to zero.