As a German, I feel deeply offended by your remarks. Expect a mounted messenger with my wrathful despatch any day now!

Come on, we have had faxes for a while now.

we _had_ fax for a while. and then came DSGVO

https://www.datenschutz.org/fax/#:~:text=Immer%20mehr%20Date....

For the rare cases where digital comms between planes and ground ATC system is done, planes run OSI Internet protocol stack to talk with ground stations.

The rest of this is essentially about ATC talking to other ATC components (for example airport's CTR zone passing a plane to another region after takeoff)

Respecting the three months notice and termination period for every procedure, of course.