Apologies for bumping a three-year-old thread, but I'm replying so anyone who is watching this thread will get a notification.
I've found out how to disable these notification by editing the iWork plist files. No blocking network access at a firewall level, and no changing an application's version and causing crashes.
I've posted it over in the Mavericks section of this forum. But it also applies to El Capitan users who can't upgrade to Sierra.
Here's a link to the solution.