Therefore, they may be treated as white for the purposes of "antiracist" hiring.
Let me be more literal for you. Does Google employ short people at a rate consistent with community demographics? What about paraplegics? People on the autism spectrum? People whose family heritage is from Ghana? People with a strong “southern” accent?
You might argue that some of these cohorts aren’t facing discrimination, but are you sure? Currently we only concern ourselves with axes of discrimination that are loud and obvious. Is the discrimination any less real if its victims don't know to be angry about it? Or does discrimination only occur when its victims are aware of it?
At what point do we declare one person’s discrimination more important than another? At what point do we declare that one person's discrimination is worthy of upending the default behaviour of billion dollar companies, and others can be dismissed as equally ridiculous to demanding a toddler join senior leadership?
Here's another reductio: Imagine if the NFL (that's American Football right?) started doing the exact same thing—requiring teams to work towards reflecting the demographics of their communities. There would cause outrage for obvious and correct reasons. And yet it's a direct parallel.
To be clear, I agree with the principle of applying active introspection to how your hiring outcomes compare with demographics. This is a good thing. But I don't agree with the argument that private employers should be responsible for fixing (or more precisely, compensating for) problems which exist upstream of the hiring process. Because it doesn't fix the problem. In fact it can make it harder to fix the problem. It papers over the actual problems so that society has greater license to ignore them.