I don't want to seem like I am defending crypto, but how is selling NFTs a scam? FTX was scam not because it was selling crypto but because it was an actual financial scam, a business breaking US laws.
He does this by using his celebrity power, as well as bringing in other big athletes (tiger woods for example) to pump up artificial demand for junk NFTs. I also think that the NFTs they sell are designed to be confusing, and the buyer probably doesn't know what they're (not) buying in many cases... although this is probably true for all NFTs.
This may all be legal now, but I think he's playing with fire. When people engage in greed fueled schemes like this, chances go up that they have engaged in actual fraud.
IMO what he's doing here is more crooked than his FTX involvement already.