I think there are two main issues here.
First, a ramjet-powered missile is going to offer great range and terminal maneuverability, but no anti-ballistic capability, which is a far more significant requirement than it was just a few years ago given the events in the Middle East.
Second, the Forward Pass/Outer Air Battle missile requires offboard sensors to utilize. The US Navy was going to utilize E-2s with CEC for that purpose, but it would require using something like an F-35 or Mojave with a tactical data link for the Royal Navy.
While I'm sure its technically feasible (not as sure about funding), it's also possible with a quasi-ballistic anti-air missile like the SM-6, which also has anti-ballistic capability in addition to anti-air and anti-surface roles. The Aster 30 Block 2 probably represents the appropriate form factor (full-diameter missile), but it looks like an exoatmospheric ABM like SM-3 instead of a maneuvering in-atmosphere ABM like SM-6 or PAC-3 MSE.