I don't think I do think a particular response implies the same for any of these, not sure where you've got that from.
I think you've arrived at the question I had hoped was implied by context in my OP. So what do you think?
It wasn't implied in your OP.
Your OP asked a very specific question -
'Is there a 'right to complain'? - which I answered.
If you want to move onto different points than stated or implied in your OP, that's fine - let's do that.
What you seem to be suggesting to me, in a rather convoluted manner, is the following:
'When there has been a disciplinary process relating to a particular child should the parents of that child be informed so that they can complain.'Now this is actually complicated as sometimes it is difficult to reveal details about a disciplinary matter to a parent without necessarily having to reveal details about other children, who have the right to anonymity. So there is a judgement call.
But there is another point - a complaint needs to be clear, focussed and with a specific 'ask' as remedy. In the case you are citing, what would be the specific ask of a complaint. Presumably the most obvious would be for the teachers involved to be subject to a disciplinary process. But this has already happened. Another obvious ask would be for teachers to be reminded about appropriate and inappropriate use of social media (I suspect what they did was already outside the policies for social media us that the teachers 'signed up' to). Fair enough, but it is quite likely this has already been done. A final ask might be an apology - again fair enough and I think they certainly deserve one.