Jacksonville was 20th in overall attendance last season, 17th in percentage sold(96.8). A ton of teams did worse than them attendance wise, and they haven't even had a game blackout since 2009, and the money Khan is spending is FAR beyond what any owner would if his team was looking to move.
Spent 10 million on locker room upgrades, spent 20 million on the scoreboard/videoboard in the stadium to upgrade it to one of the largest in the world, he's opened up foundations to help out the city of Jacksonville and it's residents financially, etc, etc.
The Jags aren't going anywhere. Both the Dolphins and Buccaneers are better candidates from the state of Florida alone to move.