DFC - Conversely, if we do not transmit any 'relevant' information and there was to be an incident, some bright but non operational spark in a legal dept somewhere might try to insinuate that ATC was negligent in not disseminating the information in the first place and that the reliance on the idea that the pilot has probably had the information from another source could be classed as negligent.
Whether a pilot asks for further info is up to them. If I'm asked for the details, I will give them but as I said before, to put out the full details of a warning on the ATIS would only lead to your colleagues moaning about the ATIS message being excessively long.
As for how many flights ask for the full details, the answer is that I just don't know. I'm not in the seat 24/7 and since we don't record such requests, there is no available data.