Well there is -- if DLC doesn't sell they don't make more no matter what they said. If the last gen systems had sold enough DLC you can bet your bottom dollar they'd be making last gen DLC.
It does not sell because people on old platforms are largely dissatisfied with the game, which is poorly optimized and has several bugs.
The discussion is not from a legal or business standpoint. It is moral.
And the problem is that they are making this kind of decisions over and over. The point is that buying things from Bioware is now risky and not a satisfying experience anymore.
Their marketing is misleading (There will be no AB and C ending, Made for PC gamers), their tech team response is slow (game took five months to be reasonably stable on PC) and you as a customer cannot count that they will act in good faith - they will cut the rope if they think they can get away with it.
It is not even just the fact that there will be no DLCs anymore for last gen, they are not even making the effort to fix the bugs that just affect a small contingent of players (in all platforms).
Giving the game for free is not just a decent and nice thing to do, it is damage control. With dick moves like that, EA is destroying the Bioware brand (and they do not care - it the developer stops being profitable they just ditch it). Microsoft spent billions of dollars to salvage the xbox brand with the Red Ring of Death thing and it was a wise decision - and MS is not even known for their quality customer support.
Things pile up and must be seen inside a context: it is not the first time Bioware disappoints and the disappointments are getting bigger. They are making it quite clear that, when they make a mistake, you are the one paying for it (sometimes twice).