I still haven't been told why (which is itself a violation of the CoC)
You're literally replying to an email telling you why in a thread where you were previously told why.
so I obviously don't know if it was discussed and agreed on by the conduct team before the ban
As you've been told several times in this thread, yes it was.
says generally the accused should be contacted first before punishment and that also was never done.
Several warnings were issued by mod team members during the discussion. I know because one of them came from me. It's true no one used the word "ban" because usually the approach is to suggest not threaten... Please stop using this venue for this, as you've been told. You already contacted board and they are (obviously) already aware of the situation. If you cannot leave this list for the intended purpose we may need to discuss extending the technical implementation of the ban.