I use a plugin to show and or hide categories based on user accounts or user roles. I did a test with one product that I placed in a public categorie, but I also added this product to a hidden category only visible to specific users / user roles.
When I click this product the section (you will also like) shows other products from that categorie. Now i'm not quite sure but i think I know what is happening. Because the category that is hidden from public is now actually not hidden anymore because the product is visible in both categories. I also asked the plugin developer this question on how to fix this issue. And i'm also asking it here to see if I can get some help / insight into not showing those products from that hidden category, and only that one product.
You can view this happening on http://rental.banoshop.eu/product/double-robotics-double-remote-presence-robot/
When you click a product in this section nothing happens because it is restricted. So on that level it works. The only thing left is not showing it at all when not logged in.
Note that I can hide it with a function "if not logged in" but other members with an account and no access to this specific category can also see this when logged in so that was not an sollution to my problem.