Julia is already being used in a number of systems with varying levels of real-time-ness. It's early days for sure, but there's a bunch of progress. It turns out lots of "real time" applications actually just need fast code. JIT compile also can be overcome since in real time systems, you generally know all the code you are going to call so you can just make a .so with all of those bits compiled and know that nothing will need to be compiled at runtime.
The coolest I know of is ASML putting Julia on their giant chip making machines https://www.youtube.com/watch?v=EafTuyy7apY. I think there's also work on putting Julia on satellites, but I don't have the details.
Also on a related topic, the PR for parallel GC in Julia just merged 4 days ago (https://github.com/JuliaLang/julia/pull/48600), so GC is in the process of getting a bunch faster.