According to PWInsider.com, the main reason why John Cena is returning to WWE sooner than expected is because once again WWE overstated how long Cena would be out of action when he was originally examined by doctors.
When Cena was first evaluated following his injury, they found only a partial triceps tear, so WWE knew all along he would not need to miss the originally reported 4-6 months, and that time frame was likely announced to surprise fans when they then announced his early return.
As we reported earlier today, WWE doctors have given Cena medical clearance to wrestle at Hell in a Cell, and at this point his bout against Alberto Del Rio is scheduled to be a traditional singles match and not a Hell in a Cell bout.
As for the reason why WWE is trying to stack the deck for the Hell in a Cell PPV, F4WOnline.com is reporting WWE feels it may have alienated its PPV audience with the last two PPV non-finishes, as Night of Champions ended with the decision being overturned just 24 hours later, which enraged many fans, and of course Battleground's No Contest main event finish.
Therefore, fans are likely to get a guaranteed Title winner in the Hell in a Cell match at the PPV, and the returns of both John Cena and Shawn Michaels.