Re: 2.0, with additions
See, I'm on the opposite of that theory spectrum. I always thought Simone's game plan was having Dinah leave, hence moving away from the buddy-flick nature of the book with Oracle/Dinah and going towards a rotating cast with Huntress as the main field agent. If Dinah had left because doing BoP and JLA was too much while raising Sin, I'd agree with your assessment; with Dinah retiring to solely raise Sin, despite Dinah also being in JLA, it seemed to fit with my theory that this was the writer finishing up the story the way she wanted how she wanted. (Mind you, I don't want to sound like I'm arguing my view/opinion is right, just that I'd been waiting for that shoe to drop since 2004.)