Apple has assembled the Mac Pro at its factory in Austin since 2013.
Actually, this sentence is "half true".
It is true that Apple has been assembling the Mac Pro since 2013, however, the factory is small (compared to ones in China).
Not only is the factory small but the "target market" for the output are for high-end music studios, graphics houses and/or Hollywood-style film production studios.
The prices are more expensive than the Made in China variety and are out of reach for the majority of the American public.
So this announcement is actually a "hallowed statement".
Biting the hand that feeds IT
