Currently, requests for access are sent to just one person:

Confluence will send an email to the a user who can grant permissions - this will be either the last user (with appropriate permissions) to edit the page, the page creator or a space admin.

If that one person is not available (i.e. on leave) then the request won't get actioned until he/she is back. The person who made the request has no way of knowing if their request has been reviewed. For example, the e-mail to the person who can grant access is generated from a system e-mail address and the out of office auto-reply from the approver would get sent to this email instead of to the person making the request.

A potential solution is allowing Space admins to elect for requests be sent to all space administrators, or allowing the system administrators to decide whether to send request access e-mails to all space administrators instead of the current logic would resolve this issue.