No need for a gun. Trouba wants a big contract and there is a widespread perception that his play has gone downhill in the last two years. If the Jets don't trade him because there is no trade of acceptable value on the table, and he comes back and plays, sulking and not playing hard will hardly show teams that he's reversing the downward trend. That will not be helpful when you're looking for a 6 year deal at $6M per...
Furthermore, Trouba is a good player but nowhere near the McDavid, Crosby, Kane, Seguin, etc. class, where a year-long holdout would have zero impact on their value to most teams. If he holds out for the full year, he will again be leaving long-term money on the table.
The Jets will miss the use of an asset if he holds out but they're not paying him a salary right now and aren't contending for the Cup this year anyway.
Realistically, Trouba's best bet to get out of Winnipeg would be for him to come back, play with Buff on the top pairing (albeit on his wrong side), play extraordinarily well and have teams willing to put up serious assets to entice Chevy into making a deal.
In short, ffh, everyone is disagreeing with your rationale for good reasons - the Jets hold all the leverage, why deal from a position of weakness when you don't have to? If no deal is forthcoming as we approach Dec. 1, Trouba is better served with signing a bridge deal and playing hard and well to prove his value - in which case, the Jets would be able to deal from a position of strength, facilitating a potential trade.
Not playing or playing poorly will only make a trade and big pay day less likely, so it really would be a poor decision on his part....