I wonder whether Apple is planning on open-sourcing the code. If they want it for internal use, then open sourcing it could make the whole project less expensive.
While you could point to the pulling of downloads, and pulling of GitHub accounts as a transitional 'rebranding', I just don't see what incentive Apple has to open source a system that is useful to bigger players and generates a lot of revenue.
I'm sure a company that's richer than many countries is really, really concerned about the cost of development.
The benefit of making sure no-one else can benefit from the technology, on the other hand...
And you're spot on about the cost of development. I'd imagine 12 - 48 hours of profits from Apple would be enough to fund its database R&D for the next 10 years.