It's great that there are a few projects that enable writing software for embedded devices in some languages you don't usually see in the space, but projects like this do not suddenly make the lang a 'systems language'. You wouldn't want to write an OS in Java or C# or any language with a GC & runtime really.

Nerves is also a wonderful project, enabling the use of elixir for IoT devices, but nobody would claim elixir is a systems lang.