When it came time for Piper to sign a contract for the Legends House reality TV show, the contract made talents agree not to do any other wrestling or MMA shows before Legends House debuted and for a certain number of days after it aired.
Legends House was filmed a while back and still hasn’t aired. Piper refused to sign the deal because his son is a MMA fighter and Piper would not do anything that could potentially put his sons career in jeopardy down the line. Piper wanted to make sure he would be able to use his name and likeness to help his son in any way.
This is why Piper isn’t featured in the WWE 2K14 video game.
This issue between Piper and company officials was only recently worked out because they want him to be a part of WrestleMania XXX.