Eh, not really. OpenBSD is about simplicity more than anything else. It's no surprise that they don't want Rust, which is very complicated, into the OS. Also rustc is super complicated, and very slow.

For example, for a time OpenBSD was trying to switch to pcc, a super simple C compiler so they could get off gcc. They eventually went with clang instead, which is not simple, but presumably the cost of using an alternative to gcc or clang was too high.