Arch is at least more likely to update to a fixed version sooner, and someone getting something with pacman is going to be used to the idea of it breaking because of using bleeding edge dependencies. The difference with the Flatpak is that most users believe that they’re getting something straight from the developers, so they’re not going to report problems to the right people if Fedora puts a different source of Flatpaks in the lists and overrides working packages with ones so broken as to be useless.
Most of the languages you’ve mentioned aren’t systems languages, so don’t make being a good language to write an OS in a high priority. More languages might be accepted in the future, but if they are, it’ll be ones that are a natural fit for the problems they’re solving.