Why is it an issue to call from a withheld number which doesn't happen to be a school phone?
Because it goes against the professional code of conduct
I have a 2:1 policy of my own - for every negative call I have to make to a parent, I find two positive things to call homes about. It makes me feel more human: telling parents their child is struggling I'd never easy or pleasant.
All this sort of "praise sandwich" " two stars and a wish" "2:1" policy etc has been shown to be very hurtful, damaging and destructive, leaving children cynical, and unable to accept or evaluate praise for a lifetime, becuase of the automatic assumption that developes that any praise is part of a cycle of leading up to something negative.
by all means, praise if it is GENUINE! but not if it is something you count up to "balance out" complaints.
There isn't a universal rule that teachers can only make calls from school phones no, it is a universal code of professional conduct. if you intend to break the guidelines for any reason, the normal thing is to have written permission from your school first, normally from the designated child protection officer.
mrz, your parents need to prioritise internet access for themselves and their children, as a way of participating in the modern world, whether that is taking the bus to the nearest library once a week, or what ever. Their children will be required to have internet access more and more, they cannot do work experience without it, for example, and they certainly can't apply to university.