...maybe...but it seems odd to me that Paizo are releasing a regional CS book that isn't tied in with an AP...I can't think of any other examples...unless of course we are getting two regional CS books associated with Hell's Rebels (the second one being an, as yet unannounced Cheliax book)...
I expect we have a while to wait before we get any confirmation either way on a Cheliax book...
Well, the Absalom book wasn't associated with any AP.
And I think there's no Andoran at all in Hell's Rebels. What I do suspect is that since Paizo did a CS line Osirion book and is pretty much 99% sure to do a Cheliax book, they'll be releasing Andoran, Qadira and Taldor books, too.
Which is great news, because several of those badly need an update and cleaning up.
This! The talking bag beat me to this thought. :)