The metal which largely respects C's semantics? For example, here are some instructions that exist to match C's atomics model: https://developer.arm.com/documentation/den0024/a/Memory-Ord...
I suspect that the OS and Architecture communities have known about one-way barriers for a very long time, and they were only recently added to the Arm architecture because people only recently started making Arm CPUs that benefit from them. And that seems like a more likely explanation than them having been plucked from the C standard.
Moreover, one-way barriers are useful regardless of what language you're using.