In order for something to be cancelled, it has to have existed in some form in the first place, even if just a plan. I'm not sure that's the case here. The only evidence it was ever planned is Musk said so. With his recent record of Tweeting nonsense, contradicting himself, apparently forgetting what he said yesterday, deleting swathes of his own ramblings, etc, Musk having claimed something is not much better than no evidence at all.
I think it's just as likely that he said that in the hope of keeping some advertisers and either forgot he said it or was lying from the start and never had any intention doing what he said. Either way, his explanation for this apparent U-turn is clearly a lie and that probably doesn't sit so well with some of the people he wants to spend money on Twitter.
Such a simplistic and idealistic view of "trying to stop other people from saying things" ignores the reality of trying to run a successful social media platform. Can you point me to an example of a successful yet completely free and open social media platform that isn't the current incarnation of 8kun? If not, why not? (hint, it's not simply because everyone except 'Q' loves busybody-riddled moderation councils)