He is trying to lower his value to the jets only.Trouba is worth more today in a trade then in 2 years to the jets with no long term contract. Who is going to give up a whole lot to trade for him if they dont know if he signs there long term either. If like some say he will sign a long term contract next year and still look to get traded then why not sign now and not risk injury if you can get the money and term you would be looking for next year this year.
Who even knows if Chevy even made him an offer this summer. How many players have signed one year into their bridge? I'd bet very few if any. Most play it out and use arbitration as a pressure point to extract more. Your trying to apply logic to Trouba that could have been applied to any number of past players on bridge deals that didn't to sign early.
I figured there was zero chance of him signing this summer barring an offer from Chevy that he couldn't refuse. Given the Jets upcoming cap issues I didn't see such an offer being made. Chevy will try to negotiate the most team friendly contract he can next summer. Trouba will likely play ball or he risks substantially lowering his compensation over the next few seasons and over his career as a whole. I doubt he wants to leave that much.