The game has moved on considerably since the original KC-45A competition win / cancellation and the KC-46A debacle. The point now is the KC-46A will take another 3 > 5 years to get right (primarily the RVS), the delivery of the initial tranche under KC-X is already years behind schedule and the production rate has been slowed down.
Options need to be considered not only to maintain a 415-tanker force at an acceptable operating cost over the period it would take to buy the next batch of tankers under KC-Y - which will take another 29 years - but also reduce acquisition and operating overhead costs by contracting out an element of the overall task using one or more of the options being considered.
Airbus already produces "flying boom" A330 MRTTs. Also, 30% of the US TRANSCOM / USAF AMC mission requirement is for "hose & drogue" [as the US DoD calls it over here] - so in the overall force mix there will be dual-method tankers - like the RAF Mildenhall 100 ARW KC-135Rs which have a "flying boom" and 2 x underwing "hose & drogue" pods (not just the "hose & drogue" adaptor on the flying boom).
Dual-method French AF A330 MRTT here:
https://www.youtube.com/watch?v=cnFj5rfVaRA
Up-to-date info on the A330 MRTT options currently offered are here:
https://www.airbus.com/defence/a330mrtt.html