Oh my goodness why would they decline genetic genealogy?
It's been awhile since I listened to this full video you're replying to, but if I recall correctly, I think the reporter said that while LE do have DNA, they won't say what kind of DNA or if it's a full profile. She reported that the sheriff told her that they are aware of genetic genealogy technology and at this time have decided to stick with other testing. Since we don’t know the state of the DNA, or whether the profile is complete, it's thought their decision may be based on factors related to that. The reporter indicated that at the time of the last presser, LE told her they had run all the DNA tests that they could do at that point. She said she wishes they were more forthcoming about what they are doing with DNA but understands why they don’t say more.
My perspective is that if they don't have a proper standard of DNA in order to run genetic genealogy testing at this particular time, but feel that technology may progress to allow it in the (hopefully near) future, it would be pretty dumb for LE to announce "we tried it and failed at this point." That would open up a lot of questions for an eventual defense about the accuracy of genetic evidence as a whole. Better to just keep quiet about the process for now. Just MOO.