Vec - I believe the rumour is that the Merlin is to replace the SK4 in toto; probably a cut in total airframes and certainly not "additional aircraft".
HiLife is probably referring to the CHF's desire for Marinised CH47, CH53K or V-22 rather than Merlin - however, with money as it is, this is probably the best "real world" solution for CHF. As usual the boys will make it work - though giving up the 50K maps might prove traumatic!
Still just a rumour though, and one I'd imagine AW will be keen to contest.