I'm speculating the stage profile has something to do with it. Flat, no significant hills or crosswinds to exploit, destined to end in a bunch sprint, so which team has an incentive to push the pace - just keep track of the breakaway and bring them back in time. The thing I find interesting is how discombobulated the sprint trains have been. Kind of seems like everyone has decided the smart thing to do is to hang back, let some other train burn itself out, then come to the front at 3 km. So at 3 km the peloton is a clotted bunch and the trains can't get organized in time? That's my guess. It has made for entertaining, improvisational sprints . . . after a leisurely day's ride.