Sheen Austin is out at Twitter. He joined the company via Tesla and took over infrastructure after Nelson Abramson.

NEW: Elon Musk emailed Twitter saying most of his Tesla work was completed this wknd & he’s available to discuss “urgent” product needs. All changes have to be signed off by him personally. “We are going to agonize until we achieve as close to the perfect product as possible”

Twitter finally sent employees who were laid off in November their separation agreements yesterday. The emails "point[ed] to a URL that was registered this morning from a vendor with a 1 star BBB rating," according to a former employee. The company then had to send a second note: "This email was an official company communication and is not a phishing attempt," it says. Twitter blamed "a court order obtained by plaintiffs' attorneys" for the delay in sending the agreements.

NEW: Twitter is cutting employee benefits starting this quarter. Commuter benefits, family planning, and meal allowances are all out. Coffee and snacks are staying, per an internal email.

NEW: Behnam Rezaei, Twitter’s head of product and engineering, and one of the last non-Elon Musk appointed leaders at the company, just resigned.

Twitter is closing its Seattle office and asking employees to work from home, per an email to staff.

NEW: Twitter is shutting down its data center in Sacramento and downsizing another in Atlanta by early Jan, likely as a cost saving measure. This means a huge amount of traffic will be shifted to its remaining data centers, which could result in increased instability.

NEW: Luke Simon -- one of Elon Musk's top lieutenants at Twitter -- appears to be out. He's been deactivated on Slack.