No, 12 is an initial production, it should increase hopefully.
These delays are entirely BAE mismanagement, which caused a crisis of confidence between government and BAE.
Resolved to BAE's considerable cost, but understandably government are keeping a close eye on the project.
MRA4 should provide capabilities in advance of the competition, the RAF are even keen to use it as a platform for long range carriage of multiple Storm Shadow stealthy cruise missiles, with a much diminished ASW threat (though not entirely gone away), this and other roles like elint and overland surveillance and C3
, are the best reasons to carry on.
The ASW role update is not a huge priority now, that could change however.
For example, during periods of high security in London, a Nimrod MR
.2 has already provided airborne 'Gold Command' facilities over the capital.