Another way to say it: The set of systems programming tasks for which Rust can be used is a superset of that for which Go can be used. Go cannot be used for real time code, as it does not provide latency guarantees. Go cannot be used for many embedded (microcontroller) systems as the runtime is required.

I've gotten Rust code to run on an ATSAMD21G18 Arm Cortex M0 (Adafruit Feather board). That board has 256K flash and 32K RAM. Go executables can't even fit in the program flash! Considering the sheer number of systems that have microcontrollers in them somewhere it would be very hard to call a language that doesn't support them a "systems" language. Maybe "applications language" would be more appropriate.