I thought this point was overstated, twitter certainly has some controversial content related rules and while as the CEO of Reddit he may have been mostly fighting macro battles, there are certainly content related things that both networks censor.

Reddit's content policy has also changed a LOT since he was CEO. While the policy back then may not have been as loose as "is it illegal?" it was still far looser than what Reddit has had to implement to gain advertisers.

I think the unstated caveat would be 'anything illegal' but yes, the point was overstated, though, I think, still stands