Others may know better but aiui, following a chat with a doctor at SRG some time ago, under the forthcoming European harmonised ATC medical proximity restrictions cease to exist.
Grandfather rights I believe for those that already have them but anyone new subsequently being diagnosed with something that could have resulted in a proximity endorsement in the past will simply no longer have a medical with all the implications that brings with it.
From the time a State implements the Requirements for European Class 3 Medical Certification of Air Traffic Controllers, they shall apply to all holders of, and applicants for, student ATCO and ATCO licences or certificates of competence. However, it is recognised that there may be individual controllers who have a particular medical condition which was deemed acceptable under the previous State medical requirements, but is not acceptable under the new scheme. In these circumstances, provided the State’s Designated Authority is satisfied that the controller is able to safely exercise the privileges of his licence or certificate of competence, the previous State medical requirements may continue to apply in respect of the specific medical condition only and his medical certificate must be annotated accordingly. In all other respects and for any new medical condition the controller may develop after the implementation date, the new medical requirements will apply.
In the interests of harmonisation, a continuous effort is needed among the ECAC Member States to minimise the number of differences from the basic requirements.
From
Requirements for European Class 3 Medical Certification of Air Traffic Controllers which details the proposed medical standards.