Actually, I feel the Genealogical Proof Standard is pretty agnostic (as it was designed to be by the BCG) toward any given period, peoples, or data types. It's really just five methodological steps intended to lay out a framework for formulating a conclusion.
But as someone who's worked with the ISO in the past, I'm a bit sensitive to the distinction between "framework" and "standard"; and my science background seizes up at the word "proof" unless it's associated with pure mathematics. I really wish they'd called it the Genealogical Conclusion Framework. 
In conjunction with Elizabeth Shown Mills' Evidence Analysis Process map, though, I think it's equally suitable for traditional western documentary information, oral histories, and science-driven data like genetics and archeology. The real trick--which is up to us; it isn't specified in the GPS--is to ferret out as much data as possible from as many sources as practicable; evaluate all the information to determine its relevance and quality (another picked nit of mine: WikiTree uses the term "reliable sources" but, technically, no source is inherently reliable or unreliable--it's just a source of information--and it's the individual datum, the bits of information, that have to be separately and collectively evaluated for relevance and quality); and a determination made as to which information makes the grade to be elevated to the status of "evidence."
As for genetics and genealogy, we're really dealing with three separate elements that only partially overlap and are often confused: genealogical ancestry, genetic ancestry, and genetic similarity. At some point as we step back generation by generation, they will diverge and never be the same. A crucial point is that last one: genetic similarity. We're made up of just four nucleic acids. We are unique assemblies of 6.2 billion of those, but if considered in very small chunks we, ourselves, are not unique. Most of us still carry almost 2% of our genomes that can be attributed to the Neanderthals. If we--as continental, subcontinental, regional, tribal/clan, and even familial populations--didn't carry genetic similarities then the popular DNA testing "ethnicity estimates" would never be possible.
Bottom line is that for DNA to be genealogically relevant (as a form of information and evidence), it has to have a reasonable likelihood of being directly and accurately attributable to a specific ancestor or ancestral couple. Otherwise it's only genetic similarity.
With genealogical relevance as a parameter, we can't go back to Seti I, even if we could get good genomic coverage from his remains. Heck, we can't even go back to the period of the Danelaw in England in 886 AD or the Battle of Hastings in 1066. By the time we're 15 or 16 generations back, even sequencing exhumed remains can't be incontrovertible evidence of direct descendancy. Genetic similarity, yes. But not genetic ancestry or genealogical ancestry.
After all, 16 generations back would put you at about 1500. The Battle of Hastings would be around 34 generations back. The entire population of Europe (not including Russia or the Ottoman Empire) is estimated to have been roughly the same in 1066 and 1500: about 61 million. So in 1500 about 1 in every 930 people alive would have been a genetic ancestor of yours. In 1066 you would have had, supposedly, 17.2 billion ancestors...but there were only 390 million people alive in the world in circa 1066. 
Nope. Not gonna be able to figure out genealogical or genetic ancestors in that maze.