I'll add to this. Before you can even begin championing your language for kernel development, make sure it can compile to all of the same architectures that C can. Make sure that programs written in your language are as space and time efficient as the equivalent C programs. These are things you can do today, if you feel strongly enough about this cause.
Once your language is at that point, then start building up your arguments to convince Linus and the majority of the core kernel developers that your language is the right choice for continued development.
Until these occur, it's all just pointless speculation.
> to convince Linus and the majority of the core kernel developers
The biggest cost is not them, it's every other C programmer, every other company, the whole industry. It's unrealistic to even think that any significant part of them is going to invest resources into another language just to gain memory safety.
I figure, if you're capable of coming up with an argument which convinces Linus to move away from C, you can use that logic to convince anybody (who is capable of being convinced by logic in the first place).
Once your language is at that point, then start building up your arguments to convince Linus and the majority of the core kernel developers that your language is the right choice for continued development.
Until these occur, it's all just pointless speculation.