agree that there is no "need" for larger tires on either creo, the difference between a 15, 25, and 35lb bike isn't all that critical to tire loads. we're talking about 10% of the total load at most. and the frame of the creo 1 and creo 2 are essentially the same weight, as you note!
however, the downtube of either creo is gigantic to house the battery, and of course it connects to the chainstays, seat tube, and head tube, so you've got a very, very, very stiff frame. much more so than anyone would intentionally design a carbon fiber frame, and while i'm certain specialized thinned up the walls as much as is wise (given that the downtube has the battery in it and also has bottle bosses!) the ride is definitely very harsh compared to a super light carbon frame, or even an aero carbon frame.
pairing it with slightly larger tires is smart, IMO, and also "on trend." but they've gone too far for most road riders, 32mm tubeless is probably the sweet spot, IMO.