I think as it is right now, there is no well known language that is specifically designed for the things POSIX shell is good at (except maybe PowerShell but I don't think it can run on POSIX).
If someone was to make one, it would have to first gain popularity in a smaller niche - idk maybe as one of the languages to write CI jobs in for some specific CI system. But if it was sufficiently good and well known, it could find its way into distros eventually.