Lars & Fis
Following the introduction of ATSOCAS a controller shouldn't in ordinary circumstances provide detailed advice on other traffic when providing a BASIC service. The new term 'Basic' Service was intended to make that clear i.e. the service will be basic.
It was decided by the CAA that to give traffic warnings on occasion during a FIS, as was the case, but not on others, caused complacency by pilots and confusion and may have been a contributor to some near misses.
When a Pilot requires detail on other traffic they should request a 'Traffic Service' or if addtionally requiring vectors to avoid other traffic then they should request a 'Deconfliction' service.
However, no one asked controllers, yet alone pilots, for their input. Virtually all controllers that I know feel that they have a duty of care and so continue to provide traffic detail during a basic service but differently others will not.
At any time a controller is busy with other things, maybe providing another user with a Traffic or Deconfliction service then expect to hear nothing when receiving a basic service, so we still have confusion and no doubt more near misses will arise!.