We'll create fresh WordPress site with WordPress Default Category installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Default Category is a a helpful workflow tool:
Enforce editorial standards for posts
A quick reference for content editors that aren’t regular contributors
Each user can have their own set of default categories
Site-wide categories will be applied if a user has not specified their own default categories
Default Category is also multisite compatible as it has been designed for a multisite environment.