Google Search updated its search documentation to reserve the right to use the OG title meta data for your title link in the Google Search results. That adds a ninth source Google may pull from for your title links.
List of title link sources. Here is list of sources Google may use for your title link:
Content in <title> elements
Main visual title shown on the page
Heading elements, such as <h1> elements
Content in og:title meta tags
Other content that’s large and prominent through the use of style treatments
Other text contained in the page
Anchor text on the page
Text within links that point to the page
WebSite structured data
What is new. The new option is the “Content in og:title meta tags” bullet in the middle.
What is an og:title. An og:title is the title of your object as it should appear within the open graph. Often social media platforms use it to decide what the title should be for URLs you share within their platform.
What is a title link in Google Search. The title link in Google Search is the clickable title used in the Google Search result snippet. Here is an illustration of the search result snippet where “How to make crispy fried eggs” is the title link: