There's no way Bioware can win at that, anyway.
If the Warden gets no mention ''OMG you forgot him/her and personally hate anyone who's ever played Origins!!''
If the Warden is mentioned but not seen ''OMG we didn't we see the Warden? Operations and second-hand accounts aren't enough!!''
If we see the Warden: ''OMG the Warden didn't start pickpocketing and muderknifing everything in sight like MY Warden would! Ruined FOREVER!!''
To say nothing of the technical difficulties of having the Warden appear. Class, race, appearance, personality, voice, equipment, everything about the Warden is a blank slate, unlike Hawke which has everything nailed down in the Keep save their appearance. Properly implementing them would take up a ton of ressources, and what for? Pure fanservice? The writers have said the Warden's story is over, so it's over. We don't need to know the details of their post-Blight life.
Plus, let's at least play the game before declaring the Warden is relegated to a single side-mission and that David Gaider is laughing his ass at us because of that. As far we know they could could be fairly regular correspondents with the Inquisitor, helping out in whatever ways they can at a distance. Would actually be fairly cool, I think. Combine that with the fact we have DA:O NPCs around, I'm pretty sure we'll get news about the Warden, without meeting him/her.