If someone only works in embedded systems that are meant to last 20+ years, should they also know about the latest Js/Bootstrap/Ember/whatever front end framewo

If someone only works in embedded systems that are meant to last 20+ years, should they also know about the latest Js/Bootstrap/Ember/whatever front end framework? C# is a mostly Windows centric, managed language which frankly, will likely never enter a discussion about embedded, real-time systems. I'd expect them to know about Rust before they know about C#. Also, how many 'competent' engineers know about the newest Fortran and Ada standards? Or have even written a single line of either?