The A-29 has been selected by the USAF for use by the Afghanistan military. From the actual article (http://www.builtforthemission.com/jax/bftm.nsf?Open):
"As the aircraft selected for the LAS program, the A-29 Super Tucano will be used to provide light air support, reconnaissance and training capabilities to the Afghanistan military."
The Afghanistan military has a very specific set of needs. They need an aircraft for a very specific ground support mission, and they need an inexpensive aircraft, but to acquire and to maintain. The F-35 does not fit those criteria. They do not need a multi-role, multi-service fighter that incorporates stealth capability or supersonic performance. The title of the post is "click-bait." There was never any chance for the F-35 to be selected for this particular mission.