Short Answer
Medical evacuation is only available for a traveler quarantined due to Ebola after the quarantine has been lifted.

More Detail
In order for a traveler to be medically evacuated they must be able to be accessed by the Medical Evacuation staff.  Because a quarantine requires a traveler to stay in a specific area, they will be unable to be medically evacuated until the quarantine is lifted. If the traveler is released from quarantine they may be medically evacuated if further medical attention is needed.