Original poster here. The question was specifically about summer camp (wasn't sure if the regular troop positions automatically extended to camp).
Perhaps the question should be "why would a Troop treat Summer Camp as some kind of separate and special Troop activity with it's own leadership set? Do units create "summer camp only" patrols? (ok, I get it sometimes a unit might temporarily combine a couple of Patrols if the participation rate is low but that should be something that is rare).
We hold elections for Senior Patrol Leader every 6 months - a Scout is welcome to run for re-election if they desire. Though not mentioned in the official literature, we do limit a Scout to two terms as SPL (the Troop is large enough to be fortunate to do so). The Patrols elect their PL's every 6 months as well. Elections are held October and March. The SPL is the SPL for the entirety of their term, summer camp included.