My understanding is that a person with decision making power at these factories are negotiating with third party repair shops, agreeing on a price, and selling authentic Apple badged components or Apple schematics to them. In that sense, it is not theft.
My understanding is that this is in absolute violation of Apple's license agreements and contracts with these factories. Those factories do not have a de jure legal right to sell those parts. In that sense, it is intellectual property theft.
If and when these factories put those components on a palette, put that palette into a container, and put that container onto a ship, and that ship sails to a Western country with intellectual property protections, Apple has reported the shipments to customs authorities and gotten them seized as counterfeit parts, despite the fact that they were manufactured as part of the same batches as parts that became devices that were sold in Apple stores. Apple's problem is that China doesn't give a shit about any objections Apple might have to two CCP sanctioned Chinese businesses doing (illegal) business with each other.
It shouldn't be intellectual property theft- Apple ought to be obliged to make these components and schematics available at fair prices to shops like Rossman's. But that's the way it ought to be- in the mean time, it is theft, and those parts are stolen. Hopefully we'll be able to get the laws fixed someday.