I wanna know if the devs actually had a plan with the OGB or if they had resolved to "figure it out later", because as interesting a plot development as it was at the time, it always seemed to me that they had written themselves into a corner with that one.
Ofc they got a plan. They cant make it cannon cause you could choose to not have the baby in origins, but for those who did choose it:
(Sorry dunno how to do the spoiler thingie, but there's spoilers in the next paragraph)
Even tho the warden wont show up in Inquisition, he will at least be refered too, talked about, most likely with morrigan/leliana (you could choose to go thru the eluvian with Morrigan in Witch Hunt, so im sure she knows where the Warden is if you chose that path). Also, it seems a leak from a premature art book release in Russia shows an image of both Morrigan and her son, implying the OGB will be adressed in Inquisition. Im not saying we will get to know and see everything there is to know, but we will at least learn something new about it in Inquisition. And well... Its Morrigan... We know that whatever she is planning is related to her son (or her son related to her plan) and whatever she is doing in Inquisition will have something to do with it. As good as she might be (after a full love relationship with the Warden) she is still a Witch of the Wilds, with mistery plans that compete with Flemeth in secrecy and mistycism.
The OGB is probably too good a plot to be dismissed with just a few mentions and im sure it will be important in future games. I dont think the old gods are really dead, even if the archdemons have been defeated by Wardens. Somehow all of them (or at least a few) have survived either in the fade or by possessing other darkspawn. In order to become a Warden you need a drop of archdemon blood to do the Joining ritual, so where were the wardens when the first archdemon was defeated (Dumat) if there were no previous archdemons to get blood from?