This was once posted before - not sure if work has been done in the past 3 years.
As Andrew Hunt pointed out, on wordpress you either embed content as short codes or you link directly to content using a URL such as http://yoursite.org/civicrm?page=CiviCRM&q=civicrm/contribute/transact&reset=1&id=1 These CiviCRM URLs actually take the page that's before the question mark and replace all the content.
Essentially if you are not using a shortcode on a wordpress page, you cannot have the title of the event, contribution, etc page display as the title. While this is not the case with Drupal, in Drupal the title will appear as it is supposed to.
Since sharing event links via social media displays the title of the event, rather than the title of the page. We always have to manually change them via facebook and other sites. Below are two examples using the calendar or civicrm event links.
The core issue is making sure that the event page displayed is actually the event title and not the wordpress page.
Using Civi 5 and Wordpress 4.9.6