No, the Culdrose units get sent on ships on jobs that other services call exercises. Even in the link you provided had one Merlin mention, I know of one more, but put in the 'region' (and I do use that term in it's widest sense) to operate simply so it can be said to be there! It's doing a job any helo could do, not justifying it's overpriced avionics in any way.
North Korea - when questions were being asked, who do you think they asked them of? Us, unsuprisingly enough. But seeing as there is no more SHAR - no-one was going anywhere near the place.
Blockades of submarines? That's practical....
We have a capability gap precisely because we've massively overspent on filling one that didn't exist in the first place, and even the NAO came to the same conclusion.