Going with Twitter, it's now X.
Since he is just an investor who picked Doge as what he decides to invest in, has every right to talk about the project on where he decides to put it in his resources, never forced any one or neither was he paid to do marketing promotion.
He's never paid to do promotion of Dogecoin and what's the reason? it's simply because he's a bagholder of it. He holds a lot of it and that's how he's determined he was in promoting it through his X's profile before. Maybe we're going to see him advertise it again since he's now known that he's probably holding more of it until the bull run comes.
I believe his a free man on this case without any form of pledging guilty.
He'll only get sued if it's proven that Dogecoin is a scam but it's not. There have been celebrities that have endorsed crypto projects and turned out into a scam and that's how they got sued.