Mostly this, and additionally, have to remember that this is how Trump operates.
He says something loud and far out there in order to force a discussion. Last time he brought this up it made some of the media platforms back the fuck off their insanity for a bit. It was brief, but it worked, and now he's striking the fear of God in them again; if instead they dig their heels in, now people in general are talking and watching. It's the same damn trap he always sets up, and somehow it gets tripped every single time.
But this is also the art of the deal. I'm sure he's well aware that repealing 230 entirely is... not popular, but that's his 'starting stance' and it mellows from there. It's a tactic where you make a ridiculous demand and gradually 'give up' parts of it until you and your opposition reach a true agreement-- one that you actually wanted in the first place, but because your initial stance was so extreme it makes the opposition think they undercut what you wanted and thus 'won'.