This is, not true.
The machines in Apple's model studio are very different from the production machines used by Catcher and Foxconn for mass-scale production.
Fun Story: The iPhone 6 bending debacle forced Apple to quickly re-evaluate using a 7000 series of aluminum in place of their standard 6061. They had (of course) experimented with this long ago, but cost and finishing concerns - 7075 is harder to anodize, and finishing is the *hardest* thing Apple dos - drove them to use a slightly tweaked version of industry standard 6061.
Catcher and Foxconn both thought this would be a nice opportunity to milk some more margin, so they told Apple they could do 7075, but the cycle time was almost 2x, so the price would go up substantially.
One of the machinists thought this sounded like bullshit, so Apple called the US distributor for the machines that Catcher and Foxconn use, pulled the identical tools they were running in prototype (in new BT30 holders), and ran back to back tests to prove out the cycle time and tool life on the same machines their vendors were using. Until this point, they did all their own prototyping and process development, but it was up to the vendors to use the competitive fight for more orders to figure out how to get the cycle down; Apple never got very specific as to the process - just the quality and price.
Well, lo and behold - 7075 had the same cycle time as 6061. The vendors were bullshitting them to the tune of tens of millions of dollars. Apple showed them the results of their testing and told them to pound sand with the price increase. Ever since, Apple has run a full-scale production lab (separate from Ive's model shop) to validate production methods and guide Apple's design and procurement decisions.
Apple's prototype shops run very high-end, hyper-accurate multi-axis machines that are ideal for rapidly turning concept sketches into machined parts. If you know CNC stuff - they are a big on Hermle and Willemin-Macodel shop, but they have whatever gear they want. Other machine shops at Apple support engineering efforts running similar equipment. The production validation lab however, uses the same gear that is used in Asia, and evaluates precisely what Apple can expect their suppliers to be doing when they move to full-scale production. These are similar, but very different machines than the model/engineering shops run - lower cost, faster, more fussy to set up, but designed to absolutely bang-out lots of parts very very rapidly.
