I believe that issue was about "dotnet watch", which reruns the compilation when a file change is detected. EnC/Hot Reload sends new bytecode to a running process and updates classes/methods in memory. EnC has been missing from non-Windows platforms from the start. An IDE like Rider can't implement Hot Reload without support from the runtime.
My understanding is that they did in fact implement it, but then ripped that code out before the release.