The default behavior of any post or page in MemberMouse is to be accessible to everyone. The content protection is only engaged in MemberMouse by Protecting and Scheduling Content. So unless you manually add page protections, the page is unprotected and can be accessed by anyone; member or not, logged in or not.
Understanding Granting Access in a Different Way
You can think of the 'Grant Access' button as the 'Restrict Access to Everyone BUT...' button.
NOTE: When adding SmartTags to Restrict or Allow access to a page/post, that will disable the protection for any content outside of those SmartTags. By placing the tags inside the content of a page or post, you are telling MemberMouse that you will explicitly state which groups (e.g. non-members, membership levels, bundle levels, etc...) have access to content in each section. You can read more about this in the linked article above.
This can be particularly helpful when placing content to encourage non-members or free members to upgrade or purchase a paid membership level. It is also helpful for those who have not yet purchased a bundle to be aware that you offer the product, while showing different content to those members who have already purchased that bundle.