I am well versed in paleontology. It's a reading hobby of mine. From the reason of a split mandible of the T.Rex to the multilayered(5) teeth of the Triceratops, to the asphyxiation death poses of many fossils...
The mammal/reptile-like classification is not based on any observable facts. It is pure speculation based on time and population theories. If it was truly a mammal, it would alter time theories by 10s of millions of years. Granted, what I would like to analyze is the soft tissue of haramiyids they uncovered in the 1990s.... but that doesn't seem to be listed under the debate.
Then you will know that the arguments are just beginning. The discussions will go on for years and the conclusions will have several versions.
The FOX News story is based on the NATURE article linked below and and it has a hi-res scan of the creature’s skull on which mammalian features, especially dental ones were observed. The NATURE article also has a comprehensive graphic of Mesozoic mammal species evolutionary family tree development over time.
“Late-surviving stem mammal links the lowermost Cretaceous of North America and Gondwana”
https://www.nature.com/articles/s41586-018-0126-y