Death of the Author doesn't mean you get to ignore everyone else, it just means you don't privilege the author's intended interpretation as the "one true meaning". You can still compare interpretations and decide one is more fitting than another, you just don't get to sidestep the debate with a quote from the author.

Frost's poem is probably a good example: Clearly it has a pervasive meaning in our culture in a way that the author didn't intend. Would it be intellectually honest to ignore that alternative meaning?