I asked support whether is it possible to HIDE certain categories from the eyes of the customers? because I wasn't able to find that on demo site.
And they replied
You can't hide Categories specifically, however you can indeed hide individual packages from specific groups (or even just prevent the Package from showing on the storefront as a whole).
So please port the same thing you have for packages to apply to categories.
Because for example if I run out of goods on one category I have to keep en empty category and mislead customers because I can't hide it and I would not like to delete and recreate a category once I get the goods.