I think you need to read the article and understand that current working theory is that it was transmitted from bats and the study the article is referring to (which is completely different/has no relevance to the origin of where it came from) bases the study upon that belief/foundation.

The study referred to in the article is about transmissibility between humans and other mammals therefore mentioning that it came from bats is a valid reference to mention when considering the possibility of reinfecting/transmitting to bat population.

>“We were hoping to see really cool adaptive evolution happening as the virus got more used to humans and less used to bats, but we actually saw that there wasn’t a whole lot of change,” said Babbitt. “Because this binding site has not evolved very much, there’s really not much stopping it from transmitting from humans to bats. If you look at the phylogenetic relationships of bats to humans, we’re pretty far apart on the mammalian tree. So it suggests that there would be pretty widespread cross-species infectivity, and the literature has shown there’s been a lot of evidence of that.”

Also the research was computer-simulation generated so it's in theory. It's much better than just literature as a simulation can definitely help model things in real life such as the way cosmic math equations have evolved in regards to black holes and gravity but they are not absolute and it's like trying to grasp at the truth by looking at a shadow of it.