Surely this must at the very least be illegal advertising or something like that. He literally owns one the largest ad platform in the world and sells ads to other people. He then uses his ownership to put an ad for a currency he has stakes in. He doesn’t just put this ad somewhere where other ads goes, but in a very prominent location, visible to all users, even those with ad-blockers, other customers don’t have the option of buying an ad placement like this.
Eloquently put.
My comment was specifically about the connection to the SEC: if Dogecoin isn't a security, then Musk isn't illegally promoting a security or violating other securities laws. Maybe the CFTC would dislike his promotion, but it's not clearly illegal for someone to use one property they own to promote/advertise their other interests as long as it's disclosed (which, as you note, Musk has done with Dogecoin).
This was also rolled out in Europe, and I’m pretty sure there are consumer protection laws there which disallow this type of behavior. A media giant cannot use that media to promote their interest in a privileged position which is not granted to other ads.