There was a theory out there (pushed back on by many scientists?) that megabats (such as the one in the report) are related to primates. On that, this from Quora. Note: Italics are my own comments. Also, I bold here and there.
This is a question [who are bat’s closest relatives] that has vexed biologists for a long time, because bats are so specialized and different from other mammals, and the earliest known bat fossils already look like bats and don’t shed that much light on the origins of their distinctive anatomical features.
We were also misled for a long time by superficial similarities in their brains and genitalia into thinking that bats (or maybe just the larger bats, like flying foxes) were close relatives of primates.
On flying fox genitalia… that I can verify. I recall an especially graphic nature film from long ago; it was on fox bats, and showed a pair of them mating. Even now, I’m still astounded by how incredibly similar the male bat’s genitalia matched that of humans (apart from size, of course) and much, much more so that that of apes and monkeys. Oh… and per wiki, fox bats in general engage in fellatio, cunnilingus, and that also across the sexes.
The answer, derived from comparative DNA studies, appears to be that bats are a single, natural group most closely related to the Artiodactyla (even-toed hoofed mammals, of which whales are a subgroup), Perissodactyla (odd-toed hoofed mammals, today consisting of the horses, tapirs, and rhinos), Pholidota (pangolins or scaly anteaters), and Carnivora (a group of mostly meat-eating mammals that includes cats, dogs, weasels, seals, and bears, among others).
Also, per wiki, fox bats have the same brain size to body size quotient as domesticated dogs.