Google has communicated by e-mail to disable social networks sections in Google News Editions:

Hi, we periodically review the functionality of Google News editions to ensure we create and support the best content for our users, and as such have decided to disable the ability to add social network-powered sections (Google Plus, Facebook, Twitter, etc.) in News editions. You own at least one edition which contains an active social section, which will be deleted on December 11th, 2018. If this is the only section in your edition, we will also unpublish your edition. You can add new feed-based content via Google News Producer and republish if you would like.

Thanks

The Google News Team