My own reading of CAP 774 which defines the new services does seem to confirm that RIS and RAS are effectively similar to the new Trafic and Deconfliction srvices respectively.
But the new Basic Service seems to be dramatically different from the exisiting FIS.
Extract from AIP ENR 1.1.2 1.2(d) Current FIS
"Whenever possible, the FISO will tell aircraft of known traffic in the vicinity and will also warn them when his/her information clearly suggests a possibility of dangerous proximity."
Extract from CAP 774 Basic Service
"Pilots should not expect any form of traffic information from a controller/FISO, as there is no such obligation placed on the controller/FISO under a Basic Service outside an Aerodrome Traffic Zone (ATZ)"
Will there be any point in asking for a basic service in most situations, or even reporting your passage past an airfield if the information is not going to be used? Especially if that airfield does not have radar, ie 95% of them!