Read the armed forces pension society link above and the through-linked preface to the forthcoming DIN. There are 2 important bits of this:
The Government respects the Court’s decision and has confirmed that it will remedy the difference in treatment across all main public service pension schemes, including all Armed Forces Pension Schemes. Any remedy must a) compensate for any previous discrimination, and b) remove discrimination in the future.
Service Personnel will not see any reduction to the pensions they have earned/built up to date, irrespective of the pension scheme they are in.
So, the way that people were administered into transitional arrangements wasn’t lawful and must be remedied, (ie grandfather rights) and no one can can have their pension reduced.
So I read that as the only possible remedy is to reinstate pre-afps15 arrangements for people who were not protected on grandfather rights. So if you were on AFPS75 you go back to that, and if on AFPS05. Presumably if you then wish to transfer onto 15 or indeed stay on it you may... it’s going to be messy and expensive.