Currently the focus is on getting the game finished.
After release, that may be one of the possibilities that will be considered (perhaps dependent on what is decided in terms of other platforms or localizations, etc). Unless there is a specific need or great idea for something to add to the story to justify a proper expansion, more mod / GM mode support or starting on another project may make more sense than DLC.
DLC is quite a loss term it can be anything from More gear to more skills etc. Do not have to be story related so long it adds to the game.
I think it's a waste to the game not to make some DLC for it. I like DOS2 and think it would be very successful and what I think it is good mostly is.
