Might not but unlikely IMO. Abby herself was wearing the same clothes she had been photographed in the day she was photographed at the hotel with her grandfather and both were wearing borrowed sweatshirts and had travelled to the trails in a vehicle belonging to Libby's sister, therefore would also have picked up touch DNA from the vehicle interior and door handles plus touch DNA from Libby's home and from any visitors to the home. It is mind boggling.
ETA. Also, if they had identified all the DNA, as you suggest, why are they swabbing suspects or obtaining DNA from people like Etter?
This is what I have thought also. Why continue to swab if they know who the perp is? They have swabbed my POI so I'm wondering also if all swabs get processed and is he in the CODIS now. I hope they are watching him.