There's nothing in this article that suggests any information directly related to Elon backing out of the deal.

It's only providing reasons why, based on his established past behavior, there are reasons he might choose not to go forward.

This is just someone speculating into a news feed.

It's not "increasingly unlikely" that Musk will buy Twitter. Nothing has happened that would change it. It's as likely that Musk will buy Twitter as it has been since the news came out that he was going to do it.

If he was going to back out, he'd be paying a billion dollars (at least) just to advertise to the world that he could have bought Twitter, if he wanted to.