The main reason Utah does this is to capitalize on what's left of Lauri's stock. They could hassle for young players but they're still trying to assess the young talent they've been collecting so adding picks allows them to keep room for their young guys while building towards the future.
Detroit gives up some depth for a higher quality pairing alongside Cade. Cade has clearly ascended to that next level of stardom and Lauri is the perfect compliment to his game. Shooting is definitely the key to success around Cade and until Ausar or Holland take serious stories as shooters its important to have great spacing for Cade to go to work