I don't use Cubase so specifics on that has to be answered by another. But generally, when a file has been transferred into Melodyne and gone through analyse/detection it is not a wav or aiff-file anymore. It's a temporary Melodyne-format working file that Cubase (or Logic) will not recognize. As soon as you "save file as audio.." wav or aiff, it is again a normal audio-file and you can drag and drop it in from where you put it.
Of course I want the same, drag and drop it right out of the Melodyne-window. But the software would have to be rebuilt to enable that de-analysing and keep saved wav-audio in the window.
It should be possible to choose save as audio and keep the file in the window so put the Q in the wish-list as for now and lets hope Celemony reads it
I would like to drag and drop audio right out of Logics arrange window (into Melodyne for example) because drag and drop is the choice of the users but I can't, yet.