I doubt his offering is a threat, but a low hanging fruit that creates case law that can be used against multiple other projects.
HEX itself i didn't see it as a security i.e by the time people could buy with ETH it would be sufficiently decentralised by the BTC claims for HEX, but then again he did launch all these sites/applications and the method of shilling its capabilities price wise....
Thing is the SEC has jurisdiction seemingly over the entire thing based on one American buying 1 hex, in traditional finance it doesn't work like that, 1 usually overseas status where operating supplants the SEC jurisdiction and only the sale itself comes under their jurisdiction and then facts and circumstances determine whether they have a case.
When it comes to the second thing 1.6 billion $.
He basically promised x and delivered y but didn't have it laid out in any contract to negate if he had to deliver y because x wasn't possible.