Update: Apple offered some clarification to TechCrunch about what the facility is being used for:
Apple has reached out to clarify that the Notice of proposed production activity at the Mesa, Arizona site relates to an application to renew the Foreign Trade-Zone status that the location already had at the time Apple acquired the site from its former supplier, GT Advanced Technologies.
Apple is seeking regulatory approval to expand its manufacturing capabilities in Mesa, Arizona – but the example it gives couldn’t be further from the vision of US-made iPhones. While the federal register notification cites printed circuit board assemblies, lithium polymer batteries and monitors, the specific additional product Apple wants to manufacture there is about as exciting as you could imagine …
As TechCrunch notes, the first new product Apple wants to make in Arizona is one that appears to be for its own internal use.
The first product Apple is intending to manufacture at the Mesa site appears to be data server cabinets — which are listed in the title of the notice. This is not a consumer product Apple sells, so would presumably be used for building out its own data centers.
With Trump’s inauguration just ten days out, there has been renewed discussion of his campaign promise to make Apple manufacture its products in the USA. President-elect Trump told Tim Cook directly that he wanted this, with Cook responding in a non-committal fashion. Both Cook and suppliers have dismissed the idea as impractical, with doubts that a move would create many jobs even if it proved feasible.
Apple currently makes the Mac Pro in the USA, with components sourced from Arizona, Texas, Illinois, Florida and Kentucky.