Steps to reproduce:
1.) Enable Staging
2.) Create 2 pages and publish them to Live
3.) Delete one of the pages then publish to Live (without choosing the Delete missing pages option)
The page was deleted from Live.
The page is not deleted from Live until we check the "Delete missing pages" option.
The problem leads to another one which would most probably fixed if the use case above is addressed:
1.) Create a site with enabled local staging.
2.) Create a page in the staging site for example "O nas".
— It creates the pages with friendlyUrl o-nas.
3.) Publish everything.
4.) The page is live. Now delete the page from Staging.
5.) Create second-page "O nas".
6.) It creates a page with friendly url o-nas (correctly on staging)
7.) Publish everything.
Result: The second page appears with friendly url o-nas1 (WRONG behavior), cannot set o-nas friendly URL even if its ok on staging.