So a factory for Duracell AA batteries might simply rebrand the batteries that to not meet their QA bar as "off-brand" batteries. The slightly defected or substandard batteries could then be sold to the consumer for a much lower price than the Duracell branded batteries, without risking damage to Duracell's brand.
In fact at times I have purchased OEM hard drives through the Apple store instead of on Amazon.
My theory being that a manufacturer would (and this is important) be more likely to send their "A" production to Apple and do a better job of screening defects.
Might not be important for a laptop bag but a mission critical part I'm willing to pay a few extra dollars.
It's not a new concept in business that the better and more important customers [1] get better product and service.
[1] Ever try to hire through a temp agency? You don't get the same crop of people that the big guys get who give them a lot of business.
And LG, for example, assembles worse monitors than their competitors, who are using the same panels LG sells them as an OEM...
As for the Tesla, eighty thousand dollar cars better be damn good. If Tesla can snag similar praise making a car for thirty thousand then I might become a fan.