Content type hub syndication is achieved via timer jobs. When you publish a content type from the hub it is pushed out by the content type hub syndication job (running every 15 minutes by default) and then picked up by the subscriber job for you web application.How to publish a content type hub site?
Now go back to the Source Content Type in the content type hub site collection. Then site settings and choose the content type which we have created. Choose the Content Type Settings -> Manage publishing for this content Type. In the Content Type Publishing page, Choose the “ Publish ” option and click on “ OK “.How does content type syndication work in SharePoint?
Content type hub is available to SharePoint web applications via the Metadata Service Application. As long as the web applications use the same Metadata Service Application, the content types will be pushed to those web applications that are subscribed to it. Content type hub syndication is achieved via timer jobs.