Original poster here. The question was specifically about summer camp (wasn't sure if the regular troop positions automatically extended to camp). The ASPL boys who were "passed over" for leadership at camp were taken by surprise to be told (at camp) that they would not be SPL and ASPL for the week. They accepted the authority of the (new) leader who did the assigning.
@ CalicoPenn -- Agreed! They'll get over it. All part of the learning.
@ Senior Member - Thank you for "The key really is that this is a choice made by the boys" -- and a good reminder to carry and use the handbook!
@ BSA Heretic - Great idea! To share with the boys.
These are my takeaways:
1) The ASPL boys could have taken ownership of the role in advance and gone to the summer camp leader before the event. That may have circumvented the situation. They are new ASPLs. Now they'll know.
2) The adult leader could have sought the involvement of the SPL and ASPLs during the preparation period. That may have circumvented the situation. He is a new summer camp leader. I hope he'll do it again and next time he'll know.
3) The committee chair (who was present at camp) could have stopped the assigning and demonstrated that this is a boy-led organization. By both his position and experience, he knows.
My suggestion to the boys will be that they go to their SPL and make sure he understands what happened. Most likely he'll go to the SM who can address it at the next committee meeting.