(CNN) — Elon Musk has completed his $44 billion acquisition of Twitter, the company confirmed in a securities filing Friday, putting the world’s richest man in charge of one of the world’s most influential social media platforms.

The company said the deal “became effective” on Thursday, as part of a filing notifying its intention to de-list from the New York Stock Exchange. The confirmation comes after a source familiar with the deal told CNN the deal had closed Thursday night.

Musk also appeared to acknowledge the takeover in a tweet Thursday night saying, “the bird is freed.”

The deal’s closing removes a cloud of uncertainty that has hung over Twitter’s business, employees and shareholders for much of the year. It also averts a court battle that was set to take place if the acquisition did not close by 5 p.m. ET Friday.

But Musk’s takeover now raises a host of new questions for the future of the social media platform, and the many corners of society impacted by it. Musk on Thursday fired CEO Parag Agrawal, CFO Neg Segal and policy head Vijaya Gadde, according to two sources familiar with the situation. He also fired Sean Edgett, Twitter’s general counsel, a source told CNN.

Despite multiple news outlets confirming the changes Thursday night, Twitter staff had still not formally been informed of the changes as of Friday morning, two Twitter employees told CNN. “Employees are left feeling completely rudderless — half our leaders are gone, those who remain are silent, and we’re watching the platform go crazy with people either joyously awaiting more layoffs or pushing the bounds of what previously was allowed,” one Twitter employee told CNN Friday.

In a tweet Friday, Segal confirmed his departure from the company. “Thursday concluded 5 years @twitter,” he wrote. “I’m grateful for the opportunity to have worked with such an incredible group of people building the world’s town square for all of our stakeholders. The work isn’t complete, but we made meaningful progress.”

Musk has said he plans to rethink Twitter’s content moderation policies in service of a more maximalist approach to “free speech.” The billionaire has also said he disagrees with Twitter’s practice of permanent bans for those who repeatedly violate its rules, raising the possibility that a number of previously banned, controversial users could reemerge on the platform.

Perhaps most immediately, many will be watching to see how soon Musk could let former President Donald Trump back on the platform, as he has previously said he would do. Depending on the timing, such a move could have major implications for the upcoming US midterm elections, as well as the 2024 Presidential campaign.

Trump said in a post on his social platform, Truth Social, that he is “very happy that Twitter is now in sane hands” following Musk’s takeover, but hinted that he would not return to the platform.

“Truth Social has become somewhat of a phenomena,” he said. “It also looks and works better to my eye,” he said. Trump previously said he would remain on Truth Social rather than returning to Twitter, where he had tens of millions more followers.

In taking steps to change the platform, Musk could singlehandedly upend the media and political ecosystem, reshape public discourse online and disrupt the nascent sphere of conservative-leaning social media properties that emerged largely in response to grievances about bans and restrictions on Twitter and other mainstream services.

Earlier this week, Musk attempted to ease some concerns about how he could change the platform. He posted an open letter to Twitter advertisers, saying he doesn’t want the platform to become a “free-for-all-hellscape where anything can be said with no consequences.”

The acquisition also promises to extend Musk’s influence. The billionaire already owns, oversees or has significant stakes in companies developing cars, rockets, robots and satellite internet, as well as more experimental ventures such as brain implants. Now he controls a social media platform that shapes how hundreds of millions of people communicate and get their news.