No, preferences are not assets, and are not supposed to be treated as such. Assets are something that resides within the project, where as the entire point of this thread is to stop Editor Preferences from being stored within the project.
That being said, the Preferences can already be exported and imported as .ini file, but with a fatal flaw that it has to be done per category, and there are additional underlying intricacies as @midgunner66 described. So if the whole system is fixed properly, then it should be possible to export the entire Editor Preferences as a single .ini file and then import it into another UE installation, having the complete preferences migrated, with no exceptions.
That would more or less make them work as sort of an “asset” if that’s what you mean.