I submitted my wife and my son's application inland a couple of months ago (with WP application for my wife). They came as visitor and their visa will expire on Oct 30 basically. Do I need to submit an extension for the kid alone?
I think your wife is covered by "implied status" but as you probably didn't/couldn't request an OWP for your son, I don't think he is covered. So, yes you probably need to apply for an extension for him at the very least.