A lot of people who buy this game this year will do so based purely on nostalgia and will likely not be watching wwe anymore.
Seeing all the old school wrestlers such as the dudleys, hardys and angle might make them think "i wonder what they are doing now and where there wrestling?! Oh TNA, i might check that out"
It actually makes perfect business sense with this years game.
Except you're still throwing it out there on a major gamble.
You're putting people in the game that will turn a profit for WWE... and it's more than likely that even if they're not a fan of current WWE... they're still somewhat of a wrestling fan... and it's more than likely that at some point, the name TNA came up, considering they're the up and coming number two company in the western wrestling scene... which means there's a chance they've already seen TNA.
So you're hoping to find someone who's been deaf to wrestling since the Attitude Era, who is willing to try watching again, who just happened to pick up this iteration of their rival's game.
The odds there are pretty damn small.
The ONLY way I see them making this gamble, is if these TNA stars are in a DLC pack, which all profit made would go directly to TNA... and I wouldn't hold my breath, personally.