If he wasn't going to be in CC then i would say if the parents were ok with it then take him but as he is in CC i wouldn't this time.

If it were me and they were very close (ie. kinder friends, see each other every week etc) then i would aslong as the parents were ok with it.
My mum has mentioned that the hardest thing when my brother died (4mths) was that people hid their kids from her, it was harder sitting there seeing these people without their kids than what it was seeing them with them IYKWIM.
We didn't go to our brothers funeral, my dad was very anti-kids at ANY funeral even up until i was about 13 and i think that made it harder on mum too.

I don't think there is a right or wrong answer, we all grieve differently and we all expect different things of others.. if in doubt then ask or just keep him at CC.