2 Answers
This is actually not a bug. Since Magento 2.2 they provide a new default integration. By activating it you can link you shop to your Facebook Page and sync your Shop to the Shop on the Facebook page.
Just ignore the message if you don't use that.
You can find it in the patch notes
Bundled extensions. This release of Magento includes the first third-party extension that we are bundling with Magento Commerce – Magento Social. This extension establishes a connection between your store and your corporate Facebook account, and creates a page with products from your catalog. When shoppers click a product, they are redirected to the corresponding product page in your Magento store.
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Here is a report of the bug - github.com/magento/magento2/issues/11374 Oct 25, 2017 at 4:54