And my point is that it's different if a defendant subpoenas you to create reasonable doubt vs the government issuing a warrant without true probable cause.
Is it? Any sort of DNA match falsely implicating you in a murder seems like it would be a big problem, even if it's a defendant looking for reasonable doubt who's seeking it. How comfortable would you be explaining that story to your family, friends, and boss? (Without further reforms, what would stop the government from treating the defendant's match as probable cause and arresting you?)
Even now, they have to have more than just a DNA match. They have to show evidence of the other elements of the crime. They have issues with evaluating affidavits to ensure they have true probable cause, but that's not an issue with using DNA in this manner.