If they believe internally Dak has peaked, the must try to get value now, before it's too late. It clears the books and gives them a chance for a quick rebuild "if" they can find an upgrade. Give Lance a year with Rush as a backup and then decide what to do with a war chest of picks. After the regular season Dak just had, he would at least give us 2 1st round picks from a team like the Vikings, Falcons, etc.
I would also see the market value of Zach Martin, if you can get a day 2 pick, you pull the trigger!