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.