I wouldn't say that's a given. For example, a similar incident occurred at Rhode Island in 1999, and the air traffic controller responsible was not fired -- merely sent for retraining before being returned to service. Like this incident, it was another flight crew that prevented the situation from becoming worse, by rejecting their takeoff clearance -- something the pilot-in-command of this Southwest flight should have done when told about a heavy 767 three miles out.

EDIT: Link. https://www.washingtonpost.com/archive/politics/1999/12/19/r...