nostr:npub1nxa4tywfz9nqp7z9zp7nr7d4nchhclsf58lcqt5y782rmf2hefjquaa6q8

In the abstract he is right, in practice it is irrelevant here is why:

With the current 80 byte you cannot get any image, illicit or otherwise, relayed around the network's mempools. Because of this it will reach miner. Therefore your have to use a service such as Slipstream to get attempt the miner yo include it directly. The miners offering this are publicly traded entities. They will review the content that you are attempting to upload to the chain since they are liable for enabling its transmission. If the content is illicit they will obviously stop any upload (and hopefully report you). At that point your are effectively out of options other than trying to mine a block yourself, which is effectively impossible of course.

So yes any transaction included in a mined block is transmitted around the network. But in practice the worst type of illegal content is just about being kept out by the current filters and set of incentives. It seems obvious therefore that it would be a grave mistake to mess around with this delicate balance by removing existing filters.