Note that Twitter's TOS are only one of the three components of the Twitter User Agreement. There are also the Twitter Rules and Policies. This is what Twitter's Rules and Policies page says:
> At both the Tweet level and the account level, we will remove any free promotion of prohibited 3rd-party social media platforms, such as linking out (i.e. using URLs) to any of the below platforms on Twitter, or providing your handle without a URL:
Twitter is Musk's fiefdom now and the rules are what he decides they are. Letter of the law is worthless here; it's will-of-the-baron rules.