Well, the memory ordering model was developed for C++ and is used in C and Rust. But e.g. C++ does not have a pointer provenance model, which is arguably almost as important in this context. It turns out one of the things we really care about with multi-processing, and thus memory models is linked list hacks, and those only work if you have provenance rules, which uh, C++ just has a shrug emoji where the provenance rules would go so that's not great. C has an ISO document, although it's not part of the ISO C standard it's just another document so far, but Rust has specified provenance.

Also, the C++ ordering model is defective in the sense that while it offers the orders we actually use it also offers an order nobody knows how to implement, so it's basically just wishful thinking. For years now the C++ standard has labelled this order "temporarily discouraged" as experts tried to repair the definition and C++ 26 is slated to just deprecate it instead. Rust doesn't copy that defect.