Agree with that CAC, I think the Boeing rep was talking about the general remanufacture process (re; transferring engines across) rather than UK-specific. It's probably not ideal for UK, given the reasons you state.
As you say, there's no need for a bespoke UK engine anymore as the AH-64E puts out ample power. FMS and off-the-shelf certainly way to go - provided AgustaWestland don't stick their oar in.