The development is an abrupt turn in the ongoing Musk-Twitter saga. Less than 2 weeks ago, Twitter's board adopted an anti-takeover provision known as a "poison pill" signaling that the directors were gearing up to rebuff Musk's offer or perhaps seek a higher bidder.
But shareholders warmed up to the idea after Musk disclosed he had lined up $46.5 billion — including $21 billion of his personal fortune — to pay for the purchase. Musk said other investors could contribute to the financing.
The deal is expected to close sometime this year. Before then, shareholders still have to weigh in, as well as regulators in the U.S. and abroad where Twitter does business.
Twitter hasn't announced the timing of a shareholder vote, though the company's annual meeting is set for May 25, which could offer a convenient time to poll shareholders.
Once a company agrees to be acquired, the buyer gets to take a closer look at its books to make sure there aren't any red flags that haven't come up via the company's public filings.
The Federal Trade Commission in the U.S., or the European Commission in the EU, are among regulatory agencies that may review the proposed Twitter buyout. The agencies generally focus on how the sale of a company could affect competition in an industry, or whether it violates antitrust laws.
These reviews can take months but generally represent more of a potential hurdle when two companies in the same industry are combining. That will likely not be a factor in the review process, given that Musk’s other companies, Tesla and SpaceX, are not social media platforms.
Still, Sen. Elizabeth Warren, D-Mass., who has called for breaking up Big Tech, lamented Musk’s Twitter deal as "dangerous" for democracy.
"Billionaires like Elon Musk play by a different set of rules than everyone else, accumulating power for their own gain," Warren tweeted Monday evening. "We need a wealth tax and strong rules to hold Big Tech accountable."
But Musk also evoked "democracy" after Twitter accepted his deal, saying that "Free speech is the bedrock of a functioning democracy, and Twitter is the digital town square where matters vital to the future of humanity are debate."
He has also vowed not to kick his worst critics off Twitter.
Musk said he wants to improve the platform by enhancing it with new features, making the algorithms open source to increase trust, defeating spambots, and authenticating accounts.
"Twitter has tremendous potential – I look forward to working with the company and the community of users to unlock it," he said.
For now, it remains unclear what will happen to Twitter's current board or management team if the deal is completed, but Musk has made it abundantly clear that he believes the company has been poorly run. That assessment strongly indicates that Musk's makeover will also include a purge of Twitter's top ranks.
After accepting the $44 billion deal, Twitter reportedly locked down changes to its platform through Friday that will make it harder for employees to make unauthorized changes.
Sources close to the matter told Bloomberg that Twitter won’t allow product updates unless they’re "business critical." Any product changes will require approval from the vice president. The temporary ban was meant to keep employees upset about the deal from "going rogue."
During a virtual all-hands meeting, Twitter CEO Parag Agrawal said layoffs aren’t planned "at this time." He did not comment further about the future of his job.
Fox Business' Lucas Manfredi and The Associated Press contributed to this report.