As an occasional amateur music transcriber I'd say the goal of transcription is not transformation. If I'm transforming, I've failed :)

Inevitably the transcriber makes decisions in how to deviate from the reference recording, be it omission of instruments, microchanges in tempo and pitch or articulation. In theory a good transcription is an exact graphical representation of the abstract sonic intent of the artist.

Of course, if you are combining voices, changing chords, it approaches an arrangement which is a more creative endeavor.