If you have created a new product free product and want to give everyone access to it, you can easily do that inside of MemberVault.

Click on "Products" and click edit next to the Product you want to give access too.  On the right hand side under "Sign Up Options", you'll see "User Access".

The top button will give access to that product to every user in your account.  (if you have a lot of users, this may take a minute)

Alternatively, if you are deprecating a product, you can remove access for those who do currently have access.