It is mostly up to the device vendors. Once ST and others begin shipping Rust examples and Rust templates, we will add support very promptly. Until then there will simply be not enough users, sorry.
I also believe that Rust is the future of embedded development. I currently use it on the ESP32‑xx platform with CLion; however, compared to VisualGDB, CLion is extremely poor in terms of usability, visual clarity, and configuration. In the embedded domain, it delivers virtually nothing out of the box, making it feel like a regression to the early days of IDEs.
This is actually planned for CodeVROOM, along with better GUI for embedded Python debugging. Given that a lot of the Rust community are Linux users, not being tied to Windows or Visual Studio should be a big advantage. But there are still more VisualGDB features that will need to be ported before adding more languages.