* HEADLINE: Swift for desktop apps
* DESCRIPTION: Swift frameworks for Cocoa controls that allow development of desktop apps in a beautiful and consistent manner.
And while we're at it, give also Google a hand on porting Kotlin apps for the desktop too. There is nothing better for a platform than allowing developers to build modern and beautiful apps to push the platform even further.
You can already use Swift in Linux (and I suppose there are already some WIP bindings to GTK). Cocoa is a totally different beast, really dependant on internal workings and semantics of macOS, and porting it would definitely take more than a single release cycle.
And Kotlin does not have any association with Google whatsoever.
If you want a single language / development framework for mobile and desktop, I think the best option right now would be React Native, given that Canonical created a Ubuntu Desktop fork.