Let me break it down for you:
Trouba no longer wants to play for the Jets so in May he requested a trade.
In September he has not been traded yet so his agent goes public with the request.
The only leverage (very small leverage) is to not sign a contract.
The Jets GM had a similar situation a few years ago with a player under contract (Evander Kane) and his trade request took 3 years to be fulfilled, after he became a problem in the locker room.
Trouba is well aware that it took Chevy three years to trade Kane despite him repeatedly asking to me moved. Why would he ever sign a contract that locks him in to Winnipeg for 6 years? If he wants out that badly he is going to do whatever he needs to do to get traded. Signing a 6 year deal to 'rot' in Winnipeg while Chevy takes his sweet ole time finding a trading partner is not an option.
Thus, if he signs an offer sheet for a 1 or 2 year deal, Chevy can either let him walk for whatever the compensation is, or match the offer. I believe once you sign an offer sheet and that offer is matched you can not be traded for a year, but that may be a better option than waiting on Grandpa Chevy to get out of his rocker, shuffle over to the phone and work out a deal 4 years from now....