When we hear an orchestra performing a well-known work, we all know, almost intuitively, that the personality, taste and aptitudes of the conductor and the orchestra are influencing the way the music is expressed. If we listen to the same piece, as played by Isaac Stern and then again as played by Itzhak Perlman, we are specifically interested in hearing each individual's interpetation of the work while probably not consciously worrying about the composer's intent.
That statement implies two things: one, that we're very aware of the performer's influence and secondly, that we trust that the performer has understood enough of the composer's intent to offer a rendition that doesn't in some way misrepresent the work.
In the case of a photograph, I agree with those who feel that labeling is important.I want to know whether a print represents the photographer's vision (as it evolves over the course of that person's life) or the vision of someone else. It's not about validity as much as it is about letting me put what I'm seeing into context. The question of whether or not our posthumous printer is in some way misrepresenting the original artist's work is subtle and probably not directly answerable. How well can any human being know another? Can anyone, even the most intimate associate, know how anyone else's tastes would have evolved? I don't even print my OWN work the same way from year to year...