Well, yeah, "manned UAVs" would just be wrong -- drone passengers are passengers, not crew, and "manned" refers to having a human crew.
(Though I suppose a long-endurance drone with human maintenance crew might be properly considered "manned" despite being unpiloted. But, then, an Unpiloted Aerial Vehicle could have the same natural initialism as an Unmanned Aerial Vehicle...)
Not that people won't butcher the terminology (ATM Machine), but even at the worse, these shouldn't be to bad...
A trip to mars would be completely automated but you still wouldn't call it unmanned if a scientist was on board that did nothing but scientist stuff.
"Manned Unmanned Aerial Vehicle" = nonsense