FA
The organisation and responsibilities of UK AIS are to found in AIP GEN 3.1
They are required to provide a briefing service that meets the requirements of Annex 15 of the Chicago Convention, and as far as I am concerned they do that. The products that they are required under the convention to provide have to conform to ICAO Standards and Recommended Practices (SARPS) of which Annex 15 and ICAO Document 8126 (The Manual of Aeronautical Information Services) are part, as do the products of all the AIS of ICAO contracting states.
UK AIS are part of NATS and provide the service on behalf of the National Aviation Authority (the CAA).
It is of course possible for "value added" products to be provided in addition to those that are required under the treaty obligations. Traditionally this has been left to commercial organisations like Jeppesen, Aerad, Bottlang, Avbrief, Pooleys, AFE, Copperchase and other providers who re-package basic AIS data to give a variety of formats from which the buyer can choose.
In my personal view it's debatable whether, in view of their privileged position, it would be desirable for AIS to become a commercial organisation that provides value added products in competition to the commercial organisations to whom it also supplies the raw data. Other people may have different views and I am aware that NATS have been investigating the economic viability of such a move. How seriously and in how much depth I am not aware.
My concentration is on improving what is provided by AIS under the UK's Chicago Treaty obligations rather than on persuading them to produce Value Added Services, which would have to be funded by users.
I hope this helps your understanding.
Mike