Well, I have to agree the way they formuled the game "completion" makes things really unclear.
As you said, a finished product should be named v1, but trying almost each new versions of the game, I really can't imagine this game in its current state can be qualified as "completed" because due to all the bugs and problems that still exist there (even if only in its main story).
There are still mentions about "next updates" in your diary when you finish the current story of a character.