It's a pretty bad move imo. I see where he is coming from, but this is going to have a ripple effect over the industry which will hurt everybody.
Cross promotion is a win-win. Publishers don't need to put in much effort and they consolidate their audience, whereas the platform gets more content in turn, so more users.
With this type of situation, when you promote any social media, you are also promoting all the others you link to on your YT, IG, Twitch, Twitter etc... You might not bring new users over there, but it does contribute with engagement.
Now, it's going to be all out war between all parties with link reciprocity. And the user experience on Twitter is going to suffer.