For me those two terms refer to different types of things. Vintage is used more to refer to older versions of a frag, often earlier formations with more backbone, greater depth, complexity, or even just closer to the nostalgic memory of when it first came out. The vintage ones might not be as "fresh" in the sense that some of the topnotes may be gone, but then again it might still be a "fresh" (ie new smelling) vintage version. A "Fresh" frag (let's ignore the application of meaning that it's an aquatic, citrus, etc) usually just means that it's bright and sparkling and the topnotes are really lively. buying a "Fresh" version of a frag is probably more applicable to one that's full composed and has all the notes intact.
For example, I have a current formulation of a frag that wasn't taken care of very well. It doesn't smell "fresh" at all in that the whole topnotes are just flat. In the drydown it's basically the same, but I really miss the whole bright clean opening that new bottles have when I test it. A vintage version may be missing those topnotes too, but I would be hunting it down because it's probably a different formulation. I might even just expect the topnotes to be gone in a vintage version.