I believe they said there would be no DLC characters. backlash against Javik as DLC was specifically cited as the reason for that.
DLC quests are entirely possible.
Certainly true, but what possible reason is there to make a big deal about it 2.5 months prior to launch?
If it was something quest related releasing in December or 2015, why not make a big deal of it then?
In fact, let's look at past dlc release dates in relation to the main game:
Dragon Age Orgins - released Nov 3rd 09
Warden's Keep (Day1dlc) - announced Oct 08th 09 - released Nov 3rd 09
Stone Prisoner (Day 1 dlc) - announced Oct 08th 09 - released Nov 3rd 09
Return to Ostagar - announced Nov 19th 09 - released Jan 13th 10
Darkspawn Chronicles - announced May 4th 10 - release May 18th 10
Leliana's Song - announced Jun 16th 10 - released Jul 6th 10
Golems of Amgarrak - announced Jul 28 10 - released Aug 10th 10
Witch Hunt - announced Aug 25th 10 - released Sep 10th 10
Dragon Age II - released Mar 08th 11
Exiled Prince (Day1dlc) - announced Jan 09th 11
Legacy - announced Jul 07th 11 - released Jul 26th 11
Mark of the Assassin - Sep 16th 11 - released Oct 11th 11
So, with the exception of the Exiled Prince for Collector's edition preorder (announced 2 months before launch)
No other Dragon Age DLC has been announced more than 1 month ahead.
If the normal schedule is typical, DAI quest DLC will be released (and announced) across 2015.
So:
The undisclosed digital content in the Deluxe edition could be a day one dlc quest (if that is still done - see EDIT).
But that contradicts the Xbox exclusive premium content - if there is deluxe edition content that can't be exclusive.
So there are two different things here, the deluxe bonus content and
the Xbox exclusive content, they can't be the same thing.
more to think about..
EDIT
If BioWare confirmed no story dlc day one that would be a good citation to capture...