I of course have no idea, but I suspect they did not want to give up on Bryce at that time and drafting another QB would have sent the wrong message to Bryce. Picking NFL QBs is a crapshoot and even sound franchises miss and I'd be willing to throw a 4th rounder to see if Shedeur can make it. I think he's better than Bryce which I know isn't saying much.
As a fyi, Carolina played its starters against Cleveland for part of the game and he still lit them up.