Currently, it is difficult to show draft work to external stakeholders. We have a preview feature, but you have to be a user in the workspace, which requires a member seat. You can also just publish a page, but then it's actually live, which is not always what you want to do to get feedback.

Guest users will be a new type of user role which will not be counted against your member limit. Guests will be able to view all aspects of a workspace, but will not be able to make any edits to sites and pages, or changes to settings.