It is an unfortunate reality that our records of music aren't always perfect; multiple editions of pieces are actually quite common and are generally well received, especially in the notorious cases of Stravinsky and Liszt. The transcendental romantic ideal prompted the desire for the 'best' transcription, one they would feel comfortable leaving in the hands of history. Little did they realize the many versions of their pieces would actually end up preserved, and in some cases performed as pieces in their own right.
This practice of publishing revised editions comes as a response to a once-basic truth: notation is the only way to preserve and communicate music. Living in the age of recording technology, this is no longer the case. Notation software, forums and blogs, youtube and other social media websites are changing the way humans pass on their music. It is now very easy and affordable to arrange music and distribute sheet music, necessary for live performance.
It is interesting to listen to recordings of composers playing their own pieces. Hear Rachmaninoff playing: Rachmaninoff piano concerto no. 2.
While the recording quality is not pristine, you can still hear details in the piano playing. While enjoyable to listen to, I would not go so far as to suggest it is the definitive recording of the piece. Rather, it is one of many versions which come from informed study in the classical tradition of interpreting works. Likewise, it calls attention to the context in which a piece is composed--be it by the composer for their own performance, like Liszt or Bach, or for other people (Tchaikovsky's piano concerto for someone else, as he could not play the piano virtuosically). As Rachmaninoff plays expressively, we are allowed a glimpse into his compositional process as he phrases the melodies just as he intended (ignoring the massive amount of sound data lost in early recording).
Indeed, the high quality recording technology of today allows us to generate accurate representations and reproductions of musical ideas. Tools like the internet and social media allow communication of these ideas on a grand scale reliably and affordably. This phenomena will alter the development of all types of music and how it is received by audiences.
In closing, consider modern composers such as Nico Muhly. While composing for and participating in live music productions, he publishes scores for performable works. On the other hand, he is also credited as a recording artist and for creating hard copies of his conceptions. Right away, we are given the "authoritative edition" musicologists have been searching for. This primary sourcing will serve to help future generations study the music being composed today.