This response goes back to my first post on the topic: such attitudes and behavior have led to successful forks of major components that ultimately subsumed the legacy work. The Rust side doesn't even have to go so far as to reimplement the entire kernel, as Drew proposes. They can simply fork, govern the evolution of the fork as they see fit, including whatever adaptations they prefer to accommodate Rust and, should their efforts yield a compelling product (to one or all of Google, AWS, Microsoft, et al.,) they can win.

Also, I don't believe the "C side" has the degree of control over all of this that you hypothesize. The Linux BDFL isn't anti-Rust, and he is endowed with an inhuman degree of wisdom that will likely prevent him from supporting irrational C dogmatists. The acceptance by Linus of a possible future that included Rust in the kernel is the start of all of this. He knew then the road would not be trouble free; he's been calling these kinds of shots for too long to imagine otherwise.