http://u.qdnx.org/file/rozzin-20160908T170443-ks39nft.html
#Google didn't so much shut down their !XMPP federation support as just stop maintaining it (which one could argue is actually worse); there's some info in "No, it's not the end of XMPP for Google Talk": http://xmpp.org/2015/03/no-its-not-the-end-of-xmpp-for-google-talk/