According to The Information, a new head of trust and safety has been appointed by Musk.
When Musk was planning to acquire the social media firm for $44 billion, she joined as a vice president of product.
During the first few days of Musk's tenure, it was reported that he asked Irwin to come back.
She moved to the security team as less than half of the remaining employees signed up to stay. On Wednesday, Musk gave staff an ultimatum to commit to the company's new culture or be fired. They will be given three months of severance if they are a part of a voluntary layoffs.
Musk and other company leaders called up workers on Thursday who were considered critical to the future of the company. Some leaders who were laid off or resigned were brought back by Musk to convince others to stay.
Insider asked if she had been appointed to the position, but she did not reply.
The former head of trust and safety resigned. Around 50% of the company was affected by Musk's initial round of layoffs, but the senior executive was a public face reassuring users and advertisers. "election integrity" was still a "top priority" for the social network.
The privacy and security unit has lost its chief information security officer, chief privacy officer, and its chief compliance officer.