presumably it follows logically that no service at all is even less appropriate for flight in IMC...
Crikey, I wouldn't have thought you'd need the first two statements to work that out!
Since FIS and RIS (or Basic and Traffic Services) rely on the pilot using visual separation, I would think it was blindingly obvious that these services are not appropriate for flight in IMC. It worries me that people seem to think this statement is a surprise.
What this statement does now make clear is; if a pilot gets airborne into Class G airspce knowing (or having a very good idea) that he will be flying in IMC, he really needs to consider the implications of the controller being unable to offer a RAS (or Deconfliction service).
I think this is a great step forward for controllers as it makes clear that the risk assessment of flying in class G and IMC lies firmly with the pilot (or airline operator). I think it will lead to more formal agreements between operators and ANSPs so that either airlines stop trying to take advantage of higher risk OCAS routings or that 'agreed routes' will be used, where higher levels of service are likely. It follows that the military are likely to be key players in these discussions.