We went over the airborne factor (including the aforementioned linked study) in the other thread a few weeks ago.
The virus, when contract by pigs, becomes airborne; as it largely infects the pigs lungs. Whereas in primates, Ebola IIRC targets the liver; hence the difference in transmission vector.
I'm not saying it is or isn't airborne; however, there have been studies to test this in primates and all came back negative. There are different strains, and different animals can transmit the disease to humans differently. Apparently, it is almost a certainty that pigs can transmit Ebola to monkeys through the air; however the reverse or primate-primate airborne transmission has not been demonstrated in the lab.
As far as the virus mutating to be come airborne; again, I don't think that's likely after researching the topic a bit. Apparently the virus would need to change it's mode of operation within primates in order for that to happen and AFAIK that has never been demonstrated to happen in a short period of time (even with exceptionally large numbers of infections). Herpes is a perfect example of a disease that infections billions and has not changed it's transmission vector.