It's not a random blog making some conjectures, Rick Hasen is a law professor who is an expert in this area and, moreover, he cites specifics statutes and DOJ information that's not all that ambiguous.
No, he doesn't. He references the $47 as 'murky legality'. What he's stating is clearly illegal is the $1M lottery also announced by Musk.
And Musk does what he wants regardless of lawyers. Remember when he tried to back out of buying Twitter...
So Musk will be fine, especially if Trump wins.