Well, with Rust tooling that automates the creation of crates from these 'core description files' (aka CMSIS SVD, System View Description), there is a large interest from other CPU vendors too so SVD seems to have become a de facto standard. For example, Espressif has SVD definitions for their CPUs (e.g. ESP32), which are definitely not ARM: https://github.com/espressif/svd, etc.