Unfortunately, there are two problems with this particular DLC. One is the speed in which it was released (its only been a week or two since the game launched and now they have their first story based DLC addressing complaints posted in magazines), and Two is the question of the DLC's quality.
The thing about the first point is more of a question of whether this DLC was planned from the beginning, and if so, under what context (i.e. whether it was meant to be in the game but the game itself had to be released by a deadline or whether this is meant to be a reactionary fix to a problem to the core game itself, of if this is Bandai's usual fare of nickel and dime-ing players); but the second point is far more worrisome since if they're getting it out within less than a month of the game's release and it is meant to react to an issue brought up by the fanbase at large (or at least the part of the fanbase they actually give a shit about), then the quality of the DLC is probably going to be highly questionable (i.e. almost entirely reused assets, an inconsequential plot line, entirely self contained rewards, poor or no balance, barely any content at all (like Arche's bad day in ToP), or a number of other issues), or if not then we're back to the first question of whether this was planned at the start or whether this was an unfortunate clash of priorities or something far scuzzier.
Unfortunately, because this is a Bandai studio, with a bad reputation for handling DLC and because this was posted in a magazine and not on a Twitter account or an official website (that's one hell of a turn around for damage control for anybody). The signs kinda point to this not really being on the level, and the worst case scenario is this turning into a crappy release that not only barely addresses the issue but was planned from the start and essentially turns the 'apology' into a 'slap-in-the-face' to the fanbase.
Edit: Fuck; beaten.
I kind of feel like you are trying to spin this as a negative no matter what the case. First of all, let's just forget about the idea that this was a reaction to fan complaints entirely because that's completely ludicrous. As you said this was revealed in a magazine. It takes time to print and distribute magazines, the stories in them are never going to be just a few days old by the time they hit the news stands. There simply isn't enough time for this to be a reaction.
So the DLC was planned from the start. So what? That's completely normal. Most companies do that. Not to mention that there is significant time between a game "going gold" (meaning development has finished) and actually releasing for the team to work on DLC, and it's not like this DLC is even out already, it was just announced. It doesn't mean the content was cut from the main game (well, maybe it builds off of ideas that were initially cut but that's also normal). I'm not about to claim the Namco Bandai is above nickel and diming people with DLC (I own Idolmaster 2 for christ sake), but that doesn't mean I have to assuming that everything they touch is automatically evil. This DLC sounds like an extra story that expands on a character's background and isn't part of the main story (no NPCs standing around saying "I have a quest for you if you would only purchase blah blah blah"...I hate that shit), and on top of that they're releasing it for free. That is exactly the kind of DLC I would like to see more of. I seriously can't find anything to complain about there.