PWInsider.com is reporting that the decision to retire the Knockouts Tag Titles was made for several reasons. One, the feeling is the company just doesn't have enough Knockouts to make the title mean something currently and they are trying to take the Knockouts roster and build them around the singles title. Two, with all the other concepts (Gutcheck, Bound for Glory Series, Open Fight Night, etc.), the feeling was that certain things had to be removed to keep things from being cluttered, which is why the belts are gone.
The TNA TV title which is currently held by Abyss is gone as well for the time being. The feeling is that they can always re-introduce the belts if needed down the line.