From the Twitter Help Center, emphasis mine:
Twitter is where the public conversation is happening, and where people from all over the globe come to promote their businesses, art, ideas, and more. We know that many of our users may be active on other social media platforms; however, going forward, Twitter will no longer allow free promotion of specific social media platforms on Twitter.
That “however” is really carrying a lot.
You know that a social media platform is really innovative when they won’t even allow their users to link to their competitors. As with everything from Twitter over the last few weeks, there are echoes of the Trump Whitehouse, where the policy people would be constantly racing to codify the random whims of their boss.
And in case the nuance is lost on anyone, I think this is incredibly dumb and will only hasten Twitter’s demise.