If you go to this link, you can find a description of the seats being sold under a PSL and a link to the PSL license:
New Jets Stadium - Reserved PSL
A quick read of both suggests the following:
The Jets clearly describe whole sections as being sold via PSL's, but they add the disclaimer that "Disclaimer: This website is for informational purposes only. The terms and conditions of each PSL will be set forth in the Personal Seat License Agreement (updated 02-09-09) that each purchaser must read and accept to obtain a PSL."
So, basically they can change their minds about what seats they are selling via PSL's at any time.
In the License, the Licensee has to aver that s/he is not purchasing the PSL as an Investment. In addition, the Jets represent that they cannot guarantee the future value of the PSL. There is no "Price List" in the license and each License is sold individually with a price indicated in the Confirmation of the transaction. The Licensee also gives up the right to a jury trial regarding any disputes arising from the sale.
So, the Jets have completely protected themselves legally and it's "Buyer Beware." The purchaser wouldn't have a leg to stand on if the Jets decided to stop selling PSL's tomorrow. A friendly jury might find against the Jets, but the licensee gives up that right in the license.
The Jets would have a huge PR problem, but no legal problem hanging their fans out to dry. Nice organization!