From what I understand these drones have gone through the correct certification allowing them to fly in a mixed airspace, alongside civilian aircraft.
Which means for the first time the RAF will be able to fly them within UK airspace, the previous Reapers were never flown here.
Interestingly the whole thing except for the pilots is contracted out to a commercial company, including weapons loading, which means the missiles do not need to conform to UK MOD air certificates it all runs under US standards.