I'm not sure what the OP means by "thriving." Is it that people are "converting in droves?" I don't see that with Eastern Rite parishes, despite the frequent publicity. There is, supposedly, a 50% convert drop out rate, anyway. If you look at how many ER parishes there are, and how few WR parishes there are, how misunderstood, not well known, marginalized, etc., it seems like nothing unusual. Actually, the number of WR rite churches has greatly increased in the last few years, especially in America. And the interest is not just among former Anglicans, and not just in the Antiochian Archdiocese. Actually, the WR is gaining global interest, with churches in New Zealand, Canada, and large interest in Britain. It looks like the general trend is for growth.