Marvel were keen to stress that this was a plan long in the making, and totally coincidental that they announced it just after DC announced their policy change, for the same month.
Marvel also commented about the recent brand extensions we've seen at the company's comics of late, with multiple titles per character. David Gabriel stated they are aware they have a "plethora of product" and that some underperforms. That they have both a budget to make and many masters to serve. However this is intended to change in January and retailers were told to look to Previews for that month showing a decreasing line count.