Some UK Police Forces have been using the larger circumaural version of this for some years in the training environment, where historically 99.9% all their shooting actually takes place.
Their systems significantly enhance the shooter's normal hearing range whilst minimising the worst of the crack from all weapons in close proximity. Its permits you to to hear a whispered command from 50+ metres made via another's headphone system.
Police marksmen take stringent annual hearing tests and its worth noting that the majority of those who eventually fail are ex-servicemen who's hearing has already become impaired through unprotected military shooting.
The only current bugbear being the need to "double plug' when firing heavier calibre weapons such as the Colt M4 (M16) and, in particular the shorter barrel LM3 derivative.
In their current form these particular headsets are too unwieldy and impractical for continuous operational use but the more compact version, as described, could, if developed with user feedback, prove to be a significant improvement. Particularly when mated to an integral comms system.
But being the MOD, I very much doubt that active servicemen will ever be consulted until its far too late to address any concerns or observations.