Twitter is now saying they officially will block links to competitor websites, including Mastodon instances, Instagram, Facebook, and others.

However, links to Vkontakte, Telegram, Truth Social, Parler, and TikTok all worked as of this writing.

@davetroy It is becoming apparent that #twitter acquisition is highly political. This is one more platform for the billionaire's feasting on the rabid #conservative following.
‘Musk’s Twitter Buy Makes No Sense – Unless It’s Part of Something Bigger’

Brexit and Trump were initially seen as jokes, but the new owner of the social media giant could pose a serious threat to democracy – and a boon for Vladimir Putin, writes David Troy

Byline Times
@davetroy Your writing is worthier than Bitcoin. #ElonMusk loses little with the Arabs on his back. I hope #jackdorsey loses his money once the world take grasp of Musk's vile and ultimate intention.