Google Talk is still compatible with XMPP/Jabber, albeit non-federated since the introduction of Hangouts (which Talk is bridged to internally). But Google using XMPP/Jabber or not does have no bearing on Facebook Chat anyway, which does use XMPP/Jabber in a (non-federated) limited way:
"Your instant messaging client connects to Facebook Chat via the Jabber/XMPP service. [...] Facebook Chat should be compatible with every XMPP client, but is not a full XMPP server. [...] As a result, it has several behaviors that differ slightly from what you would expect from a traditional XMPP service" https://developers.facebook.com/docs/chat/
I tried to connect with Kwakwa and the jabber plugin to see if it was wrong, but it does not work maybe something wrong anyway now I'm using AmIRC with a bitlbee server.