Ok perhaps you mid understand me. Pilots should be absolutely clear about the service they have requested, and what is provided by the ATCO and what is not. Quite often they don't.
At the same time, ATCO's should not imply that an aircraft on a Basic is being monitored on radar and therefore give the pilot a false sense of security.
When I say Radar Derived Traffic, I mean passing traffic as you would to you aircraft on a TS/DS.
For example; Traffic 2 o'clock 6 miles, crossing right to left etc.
If I have the capacity to pass traffic to the Basic Service traffic as well, I would not pass it in that format. I would instead pass it as traffic overhead dinglydell tracking northbound similar level.
That way you do not imply he is being monitored on radar, but he has situational awareness.
The key point is that an aircraft that has requested a Basic service should not expect any traffic information. Or get the impression his flight is being monitored, and therefore reducing his\her lookout.
If aircraft are given timely traffic information, they will normally requested to climb descend or change track to avoid the receprical traffic anyway.
If we go back to giving aircraft a higher service than requested, Ie the old FRISing, the changes implemented may as well be scrapped, because pilots will have a false sense of security.