I think the safety of those tools as a static, unchanging code base is not a major concern, but when you're writing and maintaining code, every code change is a potential source of new bugs, and Rust does eliminate large classes of bugs as things to be worried about.

That said, I actually think that it's pretty likely that switching to using the Rust tools is going to turn up quite a few new non-memory-safety-related (ie: logic) bugs.