Lemme translate that from Writer into English.
The Calling happens at the speed of plot.
If they want him to have lasted long enough to appear in DAI, then he will have. Simple as that.
Pretty much, I didn't really say anything about my personal preference on this or anything like that, just that I'm a little surprised that his body is holding out and that he's already lasted about 10 years already ( I don't mind him possibly being in DAI).
I just don't see him living after DAI ends and depending on how they handle it could be another great piece of writing if he goes down doing something heroic or something for the greater good or something else.
^ That just seems like a convenient (and justifiable) way for the writers to have some breathing room in terms of when characters have their Calling. For something like supposedly-inevitable death, it's probably a wise move to introduce some flexibility into the timing so they don't contradict themselves later on or feel forced to kill someone off.
(Speaking of which, I have an awful feeling that the Warden companion will be close to their Calling, in Inquisition.)
I agree with this aswell, and i'm thinking along the samelines as you in regards to our long rumoured grey warden companion nearing his calling for one last mission like a few characters they've done over the years.