Is there an AR that addresses when an NCO can call a squad meeting to put out information?

There is no such thing as off duty. Things happen at a moment's notice. If that NCO has info to put out, its because someone over him has just given it to him. It sucks to be punished as a group, but that means the squad especially the team leaders are no doing there jobs. Its time to be a team and shape that soldier up.

Mennn,
You're Soldiers 24/7, I'm sure you heard this before. What you all need to do is to square away this individual so your NCO doesn't have to keep doing this. That's good old Army training right there...one messes up, the rest of you pays. It is what it is. Do you really think your NCO wants to take these measures to get a point across? He probably hasn't recommend this Soldier for an Article 15 because there is no regulations about this sort of things so, he has to bring you guys in at some crazy time. Shoot, I remember we had a CSM bring all the NCOs from the whole Battalion on a Sat morning for good NCOPD. Our 1SG did it also. You see, Soldiers don't realize that us NCOs go through some stuff too. You guys need to square this individual away.

You are a soldier 24/7. I don't necessarily agree with the time, nor do I really agree with mass punishment for one idiot, but yeah, your NCO can call you in. I advise that you guys square away your buddy so you don't have to deal with this kind of stuff.