This is not borne out by practical experience. While we've not experimented much with Rust, our Java deployments are significantly larger than other native languages like Go (and I expect Rust would actually be a bit smaller than that since it requires less runtime than Go).
JVM deployed binaries are large, not especially because the bytecode is large, but because you have to ship all the bytecode for all your code and all its transitive dependencies; there's no linker and the semantics of the language make it essentially impossible to statically prove that individual functions or classes aren't needed. You can trim it down with tools like Proguard, but that's a non-trivial undertaking and prone to error, which again you won't know until runtime.
Plus the drawback that you need a relatively large VM to run a JVM binary, but you can run Rust binaries completely standalone (out of a scratch container if you want).
> Go has the advantage of memory safety (via GC), plus better concurrency safety, which is lacking in Rust.
I'm curious what you mean by "better concurrency safety". My understanding is that Rust attempts to statically prove that concurrent accesses are safe (e.g. https://blog.rust-lang.org/2015/04/10/Fearless-Concurrency.h..., especially the section on locks). Go does nothing of the sort - it provides some nice concurrency primitives and tooling to detect data races, but the compiler does nothing to actively prevent it.