It's a moot point whether art's effect on the audience _should_ be influenced by what (we think) we know about its source. It is. It must be, since its effect (the regard or disregard of the artwork) is part of the audience's perceiving the art.

Could works of art even exist, as art, without the audience? (Even the artist is the audience in the moment of looking on his work and finding it good or otherwise.) If one beautiful leaf, framed or photographed, is art, then are its fellow leaves discarded because they were not art, or because they are not regarded as art?

Should a flower pressed by your child "just for you" be regarded more than one found in a second-hand book?

Should a slasher film have less artistic value (I assume there are people who would find artistry in some such) if the filmmaker goes on to act it out upon innocent strangers?

Does a possible Rembrandt's value truly change as you hear more about who may or may not have painted it, or is there a true value inscribed in heaven, which we mortals merely seek to approximate?

My view is that art is a dialogue between work and audience. An artist is whoever (by whatever labour) causes this dialogue to take place; each beholder is co-creator of the art he (she) experiences. The true value of this art is relative, changing with the context, from person to person and from moment to moment. If a tree falls unheard in the forest it may make what I call a sound, but if a leaf falls unseen or unappreciated it is not what I call art--unless God sees it, which would make it (and the whole universe) art. From His perspective only, of course.