Suppose license expires today, will users be able to view dashboard or worksheet which published on the server?

If Tableau Desktop license expires today, then you cannot access the dashboard or worksheet because the username on the server will have to unroll unlicensed.

But others can access because the site admin can change the ownership to another person, so the extracts do not fail.

If the Tableau Server license expires, users will not be able to access or view any dashboards or worksheets published on the server. Access to Tableau Server functionality, including viewing and interacting with content, is dependent on a valid and active license. Once the license expires, users will be restricted from accessing the Tableau Server until a valid license is renewed or applied. It’s crucial to ensure that the Tableau Server license is up-to-date to maintain uninterrupted access to the published content.