Simply being open doesn't make them good open source projects. Luckily the SPI shouldn't need to conform to Apple's release schedule, and should operate mostly independently, so the worst aspects of Apple's open source projects will be less of an issue.
Even simpler, this is a "no Scotsman" scenario. Apple has unprecedented contempt for Open designs and software standards, even compared to the pitiful example that Microsoft and Google set.
Unlike them, Apple takes a stance of contravening the public good to emphasize lock-in. They refused USB-C for as long as possible to sell licensed serial connectors that their Macs didn't even use. They fought tooth-and-nail to politicize the free distribution of software when the EU wanted to enable sideloading. They abandoned open initiatives like Khronos, for no reason other than to screw over cross-platform developers. They give Safari special OS entitlements that they refuse to extend to competing mobile browsers, and then justify it as if they can't write a safe OS.
There is no company on planet Earth that goes this far to undermine FOSS. Apple is the fakest Scot.