Three adventure paths, novels and now a sourcebook in one year. I'd say you're not exactly starving for material. One year into Golarion, how much more setting material did you have?
Never minding that why would I bother with a setting guide when we have Candlekeep and the FR wiki. Just how much setting material do you need?
I'd be happy with just a really well done FRCG for 5e, and more good FR novels, I'm not greedy, I don't expect dozens of FR RPG books.
I'd trade all the APs put together, for 1 FRCG. That's not a shot at the APs, I know they're great for some people, but they're a poor piece meal subsititue for a FRCG.