He has to find out himself (with a bit of help) that the kids in the pull out are the cool kids.
Sometimes you have to let them take it a bit to far so they understand why you are reeling them in. Like you said he is 6.
If you put limits on my ds when he was 6 he would take it right to the edge, every time. If he could have 5 slips for being talkie in class he would get 4, maybe all 4 on the first day and then be good the rest of the week. I let the teacher handle that stuff.
I dont see it as such a bad thing either.