As far as I understand it, it's mainly just a name change "to eradicate ambiguity" with the existing phrases...or something like that!!
FIS = Basic Service - BS
RIS = Traffic Service - TS
RAS = Deconfliction - DS
BS available everywhere, in Controlled Airspace and outside CAS. DS & TS outside CAS available to both VFR/IFR. Receivers of DS & TS are assumed to be capable to comply with any ATC instructions, eg. expected to be able to comply with IMC if ATC instructions cause an a/c to enter cloud.
As for asking for a RIS after next thursday, I doubt you'd be the only one, and traffic permitting, a Traffic Service offered in its place.