I'd love to hear more information on this! In my mental model, you could just use Go to replace your Python utilities, but Rust might be workable for your core (or at least its designers would like it to be and would like to know why it isn't).
So the biggest challenge with moving to another language is reproducing the same low latency and high performance we've carefully designed in C++ to a Rust analogue... which given we haven't really used Rust enough yet to have a total sense of this, is hard.
In the long future, I can see Rust working in gradual stages -- but of course focusing on biz objectives is better first when we know how to write high perf C++, hence spending time to play with Rust on side tooling or other smaller projects.
From what little Rust I've written so far I really do like it, so hoping that I can incorporate it more