Mr. Musk leaned into that freedom after his decision was communicated to the company on Saturday morning. He proclaimed on Twitter that he was in “goblin mode” and suggested changes such as removing the “w” from the company’s name to make it more vulgar and opening its San Francisco headquarters to shelter the homeless. He later deleted some of the posts.

“This is not typical activism or, frankly, anything like activism that we’ve seen before,” said Ele Klein, co-chair of the global Shareholder Activism Group at the law firm Schulte Roth & Zabel. “Elon Musk doesn’t do things that people have seen before.”

Patrick Gadson, co-head of the Shareholder Activism practice at Vinson & Elkins, another law firm, said he felt sympathy for Twitter. “I would never want any director that I represent, or any director at all, to have to deal” with this situation, he said…

Inside Twitter on Monday, employees were dismayed and concerned by Mr. Musk’s antics, according to half a dozen current and former workers, who were not authorized to speak publicly. After the billionaire suggested over the weekend that Twitter convert its headquarters into a homeless shelter because “no one shows up anyway,” employees questioned how Mr. Musk would know that given that he hadn’t visited the building in some time. They also pointed out that Mr. Musk, whose net worth has been pegged at more than $270 billion, could easily afford to help San Francisco’s homeless himself.