Are these fixes experimental? There must be a reason why they aren't in the main distribution.
As far as I am aware of how the Linux kernel is structured, these patches would have to be submitted as BSP 'quirks'. Most of the ICs (such as the audio IC) that Apple used are standard components with Linux drivers available, but Apple often uses different pinouts or configurations requiring modified (patched) drivers to make them work.
In the current state I don't think the patches meet Linus's quality standards to be accepted into the kernel, but it shouldn't be too hard to polish that up.
Should be a fun project to work on of you are looking at contributing to the Linux kernel. You'll need basic knowledge of electronics and embedded systems, but it shouldn't be that hard. Judging from Louis Rossman's youtube channel the schematics for each Macbook board should be available.
Heck, now that I think of it: I would like to give it a try, if only I had a Macbook available to do this with.