If the root of the problem is task-avoidance due to lack of challenge in school, then deschooling can help. If the problem is lack of unstructured time to play/explore/think (which is vital for healthy child development), then deschooling can help.
However, given the costs for a child who is otherwise doing well in school and craves social interaction, I would be reluctant to pull him from school as long as I can reasonably suspect that the problem is the latter. The more elegant solution there would be to scale back on the after-school activities. Not only would it give him the space he needs to be himself for several hours a week while preserving his social standing, but it would also reduce stress on you, and save some money.
So basically, before I would pull him out of school, I would start cancelling certain after-school activities.
We have a DD7 with a lot of drive and diverse interests, too, and we've acted as a brake in this way, when she starts pushing to go overboard. Once she has enough activities going, assuming there are no other scheduling conflicts, we offer her a choice... if you want to take up this new activity, pick the one that will end. We've also found that on days where she's overscheduled, she blows up. For example, her drama class ramped up to 3-hour nights for the week before her performance, and the first night, when it was time for bed and she realized she'd had no time to play, she was very upset. So, we pushed bedtime back an hour (yay homeschooling) and reminded her it was only for a week, and she was fine.
She gets it now, and has even been able to act as her own brake from time to time. This past summer, she declared she wanted to do nothing... no classes, no sports, no camps. Just play. And proving how constructive that can be, she learned to roller skate, and swim underwater.
