1. Hogan somehow using it's launch to generate interest in him (look at Kim K, Sex tapes make people talk, whoever you are). This will in turn generate interest in what he's doing currently (pun intended). Yes, we know it was "mentioned" seven months back, but the question you want to ask is; Why has it taken so long to actually see the light of day? I've seen plenty of celebrities hide behind false law suits. Didn't Vanessa Hudgens and Rihanna try suing over naked pictures that they first claimed "wasn't them"? It's deference.
2. The company have some wrestling knowledge and know BFG is TNA's biggest PPV of the year. They know that Hogan is currently doing promotional work AND has just signed up for another TV show (A reality restaurant show) and has recently bought a "beach shop", his problems with his wife and the incident with his Son several years back. the company that owns the tape are just taking advantage while Hogan is still somewhat relevant. Basically, release it while he's "hot".