you could also have the console on our own machine with 1+GHz that passes code to the embedded box to execute, or one of a million other variations on this theme. but nooo we gotta LARP about how well we support legacy systems which is why are systems are so broken after doing this for 50 years. oh yeah and embedded is dead, it's just high end boxes with ubuntu on them now. and last but not least i hope to god i never have unix on something that actually needs to be embedded for all of performance, stability and security reasons.
I've looked into Oil a bit, and I think Andy has the right idea for how to go about updating the legacy scripts. I've written a few local scripts in Oil and it's a definite upgrade from Bash.
A very hard thing to do though is the requirement of generics.
If everything is typed, you may have functions that take an argument and produce another value of the same type for instance. And generics are really, really hard to implement correctly.
Oil is first thing that came to mind reading article. Interestingly the submitted article and the one you linked open in similar way with two bullet points saying shell is made of two things.