This will remove them as your friend. It should be noted that Xbox Live will not consider two people "friends" until both of them add each other or accept friend requests (a la 360).

Roblox is introducing age verification for users in order to protect younger players and keep them safe while using in-game ...

The Friend List allows you to register new friends and view and manage the friends you already have. It also allows you to add friends you have recently played with.