I still think it's Sakura because DNA in Naruto is thrown around more than a joint at a stoner party.
Honestly, Sasuke himself has Juugo's DNA, Zetsu DNA (by extension Hashi DNA), and Kabuto DNA in him. And let's not forget that Kabuto DNA itself had Juugo, Suigetsu, Karin, and Sound 4 DNA in it when Kabuto was healing Sasuke during the war. Sasuke has traces of DNA from everyone, so I don't believe a DNA test is really helpful.
Plus, this style of writing is all part of the rising action. Inside a story, you generally have the Intro, Rising Action, Climax, Falling Action, Resolution, and Denouement. Within Gaiden, we have not yet reached the Climax (otherwise known as the "point of no return"). For this reason, I still believe that this whole side-plot of Sarada's lineage is nothing but a red herring.
Finally, there's other things to consider. We don't know what Suigetsu used in the test, and knowing Karin (who has been shown stealing stuff belonging to Sasuke, including a towel with his sweat on it), it could very well mean that Suigetsu used Sasuke's DNA. Do I honestly believe Suigetsu made a mistake on the DNA test? No, of course not, that would be stupid writing. I'm very keen on the whole DNA issue though as a whole considering Sasuke literally is a cesspool of DNA.
All I'm saying, the end of Gaiden has to yet to happen. Until such time as when this plot is over and has a resolution and it shows no more relevance within the story, the argument can be made. Let people choose to believe what they will, because despite whatever sides may seem correct or stupid, it's not over until the final call has been made.