As reported by Ginny Marvin at Search Engine Land yesterday, Google quietly posted help document informing AdWords advertisers that Google is dropping the social extensions today, December 10, 2015.
Google said this will remove the Google+ follower counts on the brand. Social information that appears next to your ads that show how many Google+ followers your website has now been removed. They use to show the follower count your brand had on Google+ and would sometimes lead to higher click through rates.
Since Google keeps killing Google+ Pages I guess the social extensions make no sense anymore.
Google wrote:
Social extensions will no longer show with ads on Google Search and search partners starting December 10, 2015.We encourage you to explore all relevant ad extensions to highlight important aspects of your business. If social presence remains important to your business, you can continue highlighting this information using sitelinks or callout extensions.
Forum discussion at Google+.