Prefixes are mostly political in purpose and don't strictly describe the aircraft mission. The F-22 was the F/A-22 for a while, the F-117 was a bomber, the X-35 was a prototype for the F-35 and thus should have been the YF-35, and the SR-71 was designated RS-71 until a flubbed presidential announcement. Everyone knows what these aircraft really do though.

Good question, perhaps giving it an actual name would reveal too much. General consensus seems to think its a 'deploy on demand' reconnaissance transport (basically a bunch of signal or optical gear in the payload that it can point at various places and then return). That would make it something like an MQ-37 or RQ-37.

The return ability also lets you collect data and store it on board for recovery later. Any sensor that can see through clouds could generate a colossal amount of data and there is never enough bandwidth!