Will we need an answer to this to help permit GPS approaches to AFIS fields?
Not directly. The problem that this operation faces is some (I think) UK-specific legislation that requires an approach service to be provided where there is let-down aid. The legislation is focused on equipment at an aerodrome but the CAA has enough other hoops to fail to jump through to stop it happening widely for the moment.
This is where EASA might be your saviour. I don't know whether this type of thing will fall high in their list of priorities but it will undoubtedly fall within their competence from December next year.