In the case of the MRA4, a consideration is the currency of aircrew, the level of which is set when constructing the safety case.
The decision to withdraw the MR2 early immediately invalidated this baseline assumption, requiring the evolving MRA4 safety case to be re-baselined and re-validated. If the RAF have gone from being able to confirm the crews fly x hours per month to "Nowt", then one cannot sign to say the safety case is valid. This dilemma faced by both BAeS and the MRA project office (with the RTSA packing his bags in the wings) would immediately become the critical path to meeting the ISD. The decision to stop flying the MR2 therefore, by definition, delayed MRA4.
Vec - My comments were based on my part of the world where delegation comes down through a different path. Yours is through Service Chiefs. The simple answer is to ask to see your CO's Letter of Delegation. I imagine one of his responsibilities relates to the above and requires him to ensure currency (including maintainers) and immediately inform his boss if, for whatever reason, he can't. That is, the requirement for ensuring constant feedback is probably his most imporant role in safety management because, of course, he has no control whatsoever over 99.9% of "airworthiness" but, like everyone, plays a vital part.