I still feel it would diminish the Warden far too much, not to have him/her in DA:I. Were three of the Warden's potential romances NOT in this game (this includes Alistair), it wouldn't be a big deal to me, but as long as they exist, it will always be a lost opportunity to not do it.
Why? Those characters are characters on their own. There are several states that Alistair can wind up in, so which one are they going to respect? Their own canon has him on the throne, I believe, so if you made him a drunk, and he's king, isn't that an adverse affect to your world state? The only difference between BioWare's canon Warden and mine is that mine was a CE instead of Dalish. She's just as dead, however, due to the US ending.
I think no one can deny that how they are going to handle Warden's story is going to be crucial to Dragon Age franchise itself.
I think it's really not. For one thing, the Hero of Ferelden Warden can be dead. Mine is. Alistair is a drunk, Loghain has to live with his mistakes, and my Warden told Morrigan to take a hike on the Dark Ritual(DR). So not having the Warden show up at all has 0 impact on my world state, and is, in fact, the intended result. In order to respect all possible variations, they'd almost have to write several games. I think it would be far easier to leave any Warden that, for example, went through the Aluvian gone. Dead Wardens aren't an issue, and surviving ones? I'd write them as falling to their calling during the end part of DA 2, or in the interval between DA 2 and Inquisition. It's not, after all, beyond the realm of possibility. Of course, I think that, rather than writing myself into a corner with the DR, I'd have killed the Warden off, making the US ending the only possible one. Yeah, there'd be some outrage for a while, but that would, eventually subside. However, there'd be a lot less "But if the Warden's not included, it breaks the whole franchise" claims.