Sure, but (1) that ship has sailed for now, there are already Rust bits in the kernel; and (2) a patch email thread is not the best place to start discussing whether Rust has a place in the kernel.
I'm 100% behind Christoph, the last thing Linux needs is the extra complexity that Rust brings. I'm fairly optimistic that Rust will never be a hard dependency for the foreseeable future.
That ship could come back to port anytime.
Basically, it's an obstructionist, uncivilized thing to hold up every discussion about a topic that you get to participate in by insisting the topic shouldn't be discussed in this forum. It's perfectly OK to advocate for the removal of Rust from the kernel, it's not ok to bring this up in every random Rust patch while the consensus is that Rust has a place in the kernel.