I feel like VS Code is eating their lunch on the sublime text front and there are too many GIT front ends for them to make a significant difference. If they license out the GUI kit- it's a win win for both the owners of sublime and GUI devs. I'd prefer a native cross platform GUI and while some prefer electron because of js+css combo- that speed would be a good factor in bringing them to sublime-kit.
So why or why not would you license out the GUI kit?
I'm not sure if sublime built their own gui.