In all the Part-FCL documents on the EASA site, proposed or otherwise, there is nothing I can see that allows for the issue of a rating such as the IMC or IR(R). The requirements for flight in IMC are an IR and the rules for getting an IR are the EIR or full IR.
There is provision to allow NAA’s to issue a licence in a way that does not remove the privileges of the licence holder so, I am guessing, that the UK CAA are issuing the IR(R) on that basis.