For the second consecutive year, Apple proved rumor mills wrong by not announcing the iPad Air 3 at its September event. Prior to that, rumors were rife about a possible iPad Air 3 release date in Q4 2016. The rumors stemmed from the fact that Apple released the original iPad Air in October 2013, which was followed by iPad Air 2 a year later in Oct 2014.
However, the exclusion of any reference to the Air 3 has led many to believe that Apple could be planning to discontinue the iPad Air lineup. Subsequently, reports have surfaced that the sluggish sales of the tablet since its introduction could be the reason why Cupertino is refraining from upgrading the lineup. Note that these are mere speculations that we can not verify independently and you should probably take them with a grain of salt.
Meanwhile, some observers also believe that Apple is probably busy preparing the device for a grand comeback with impressive specs. If this prediction comes to fruition, the iPad Air 3 specs might include a keyboard similar to the one with the Microsoft Surface Pro hybrids. Odds are also high the tablet will get rid of a few millimeters and sport a high-grade aluminum casing to prevent any annoying bending issue.
Another possibility is that the iPad Air 3 could be only an entry-level iteration of the iPad Pro 2. Note that all these are mere speculations that we can not verify independently and you should probably take them with a grain of salt.