It is worth adding that the submission of a satety review mentioned was a condition of continuance of rating issue until 2019 and does not mean that acceptance of the safety report means anything for the continuance to issue IR(R)s after 30th April 2019. The report was submitted by CAA in 2017 and the situation remains that the IR(R) will not be able to be added to EASA licences after 30th April 2019, although stictly speaking the IMC rating can be added to UK CAA PPLs as long as the CAA wants but that then limits usage to non-EASA / Annex II aircraft and the query about are any such aircraf cleared for flight under IFR in IMC.
I would imagine there will be a rash of new applications, revalidations and renewals around 30th April 2018 to enable flying under IFR in IMC using the IR(R) in EASA aircraft until 31st May 2020!
PPL/IR Europe published this research
done last year.