The FTC could file a lawsuit against Microsoft by the end of the month if it chooses to do so. The FTC remains skeptical despite the fact that both CEOs have already been deposed.
The report says that there are a few steps to go before the regulators act. The deal would face antitrust challenges in the US, UK and the EU if it happens. Microsoft tried to assure regulators that it wouldn't hurt competition in the gaming space when it bought the company.
If the FTC brings a suit against it, it will be fought by the company. It's absurd to suggest that the transaction could lead to anticompetitive effects. The U.S. gaming industry will benefit from the merger.
Microsoft has basically been in an all-out PR battle with its competitor, Sony. The deal would give Microsoft control over Call of Duty, though Phil Spencer, head of Microsoft's Xbox division, has said that Microsoft will continue to make games for Sony's consoles as long as the company sells them. It is possible that the decision was made because of pressure from the public and Sony after Jim Ryan said that Microsoft only offered to extend Sony's existing contract by three years.
There has been a fight between the companies. Microsoft accused Sony of paying developers to keep their content off of its Game Pass service, and just this week Sony argued that Microsoft's master plan was getting everyone to move over to XBOX before jacking up prices. Both companies will likely repeat their arguments to regulators. It seems like the list is getting bigger.
Update November 23rd at 9:09PM: Added a statement from the company.