According to Joe Reedy with the Cincinnati Enquirer, the Cincinnati Bengals say that "tickets are still available", but no announcement is expected until Thursday morning.
If it's a sellout, it would be the fifth sellout dating back to the regular season finale against the Baltimore Ravens last year. Not a sellout and the city of Cincinnati, Dayton and Lexington and any market within a 75-mile radius of Paul Brown Stadium is blacked out.
However more likely is that the team will request and be granted an extension to sellout by Friday afternoon, roughly 72 hours before kickoff.