There isn't much genetic research on the puma (FYI: puma, cougar, mountain lion, catamount, panther... all the same thing, just depends on where you are and who you talk to). The scientific community seems to be quite torn about taxonomic assessment and there has been much debate around subspecies distinction, particularly in the case of using cougars in Texas to repopulate the Florida panther population. Some say they are distinct enough that they shouldn't be hybridized while others say they are the same so one can successfully repopulate the other. According to the Federal Register, "the best available information continues to support the assignment of the eastern taxon to Puma concolor couguar as distinct from other North American subspecies" based primarily on biology and life history.
The proposal to remove the eastern cougar from the endangered species list does not affect the status of the endangered Florida panther subspecies, a cluster of conservation genetics issues to discuss in more detail at another time. But, although the extinct animals will no longer be protected under the Endangered Species Act, which is intended to save animals and plants that still have a recorded population, it will also no longer be able to be used to protect similar animals, such as the Florida panther. Not sure if that matters since the Florida panther is already protected (and possibly diluted with Texas cougar) but its interesting nonetheless.