Doing a tag and trade requires the player's cooperation but isn't that hard to get. Most players want long term security on a multi-year contract. If the Bengals tag Tee next February and trade him to say the Patriots, they get a WR1 for their new QB, Tee gets a lot more money than the Bengals will pay, with guarantees, and the Bengals get an early 2nd round pick. Win-win-win.