Footnote #1 suggests the author is concerned with solutions to the availability of CSAM. In this light the ownership of the NFT is actually irrelevant. Anyone can read the data in the NFT. That data will either point to CSAM or it won't. The problem, if there is one, would be with anyone with a copy of the blockchain's ledger – it would have nothing to do with the ability of anyone to update the ledger.