It speculates that Rust would help. That is very far from demonstrating that Rust would actually help.
Rust would certainly not help in this instance, because nobody is writing pty handling code in Rust. I.e., using Rust in place B does not help with bugs in place A. Any expectation that Linux would get more secure if some new code were Rust is optimistic to the point of fantasy.
The best possible outcome of allowing Rust in kernel code is that the kernel would not become even more insecure as a result of the added Rust code. That would be good, by itself, even if not what we really want. But whether even that would be achieved in practice is still to be demonstrated.
The best possible outcome of allowing Rust in kernel code is being able to guarantee type safety, memory safety and perfect concurrency where it's applied. Those 3 pain points are where C fails right now, and it's part of the reason why scheduling on Linux feels 'worse' than Windows or even MacOS at times.
Rust would certainly not help in this instance, because nobody is writing pty handling code in Rust. I.e., using Rust in place B does not help with bugs in place A. Any expectation that Linux would get more secure if some new code were Rust is optimistic to the point of fantasy.
The best possible outcome of allowing Rust in kernel code is that the kernel would not become even more insecure as a result of the added Rust code. That would be good, by itself, even if not what we really want. But whether even that would be achieved in practice is still to be demonstrated.