Hopefully Rust will eat up the real-time domain, at least for tasks which aren't best served with formal or model-based methods.
It might already be usable, most of the essential pieces seem to be in place. No GC, many parts of stdlib, typed arena for memory pools etc. Move operations and immutable by default should reduce tendencies for defensive copying.
But best-practices, documentation and tooling for real-time is not on par with C++ yet. Though real-time is an underdocumented art in general..
But it will be an up-hill battle if not working alone, unless one is working in high-integrity related industries.