Sorry your son got pushed through Weblos too fast. Not going to summer camp really put him behind. Too bad you and your son did not have a good understanding of the scouting program. I have seen it a lot, very few Cub scout parents understand the scouting program.
The best advice is have your son go to meetings and outings if he wants to. Hang out with his friends. Take advantage of the outings that he is interested in. Advancement is HIS decision. If the troop program is run correctly, he will complete requirements just by attending meetings and outings. He is a very young scout, and will probably feel a little out of place, especially since he missed summer camp. He is way to young for any kind of responsibility at this point, he needs to learn all the basic scout skills first. Good luck to him, hope he sticks with it, It will be worth it.