Hanna could very well be a surprise cut. He improved as a blocker last season, but I think it's a contract year for him. I don't think he's done enough to warrant keeping as TE3. My guess is Dunbar will be a surprise(but not really!) cut. DMac can do everything Dunbar can do and more with more size. If Days is stout enough and willing enough to lead block, he could possibly serve dual purposes as RB4 and FB making whoever the current FB is expendable along with Dunbar, saving a roster spot.
Surprise keeper in this scenario would be Synjyn Days. Not really expecting much, but an UDFA rookie power back who knocks someone else off the roster would be a shocker!