If any Form page is already published, you will get the “Draft” option here. But the list Form is in the ‘Draft mode’, you will get the Publish option. 
If you select multiple form records containing draft and published status, then all those forms will be converted to published status.
If you have selected all the published form records, it will convert to the draft mode.
Note: You can move the form into the ‘Draft’ mode only if the list is not used in the Page Builder for a specific page.