I think the key issue is that a new more effective weapon with greater long term capability has been selected. Yes my armchair preference was for the 127/64 but I’m sure the Mk45 Mod 4 will be more than adequate.

EDIT

I still think it would make more sense to ditch Phalanx and DS30M Mk2 and fit BAE 40 Mk4 which could fill the role of both systems across the fleet.