IMNSHO, the relative dearth of information about religions, especially Real ones, in the Sixth World is a matter of twenty-five years worth of writers and line developers very wisely 'not lighting a sparkler in the powder room'. Religion is a very, very hot-button topic; approaching it in anything like decent detail would take major books for the top five or six 'types' of religion (Christianity, Judaism, Islam, Hinduism, Buddhism, and maybe something else ...), and here's the kicker - people would be upset no matter how you handled it, and in fact there's a good chance of pissing off people who don't even play the game.
Staying away from that particular Great Dragon, talking only about 'new since the Awakening' and/or fringe member groups of the RL-established religions (e.g. the New Templars, Sylvestrines, etc.), or getting in-depth with brand-spanking-new religions (Church of the Dragon), may not be a matter of conscious policy, or of policy at all, but it's IMO a very wise thing. "There were problems, there was some splintering, some Balkanization was caused, etc. etc." And then you step away, and let the GMs handle it in their games however they want.