Oooh. If we are guessing, let me throw one out there:
AD wants to retire after playing a season or two with the Steelers. He had also gone from, "absolutely I'm back" to silence and rumors with Jourden. The Steelers are low-key going for it with the acquisition of Wussel at the league minimum. So, the move is trading AD for a haul and using some of that haul to get Mack and/or Surtain/Sneed.
Don't think it's happening, don't want it to happen, but if we're just throwing ideas out there that MIGHT happen ...