Eh...I doubt it. Wagner would come back for a retirement match or at least a run-in against Rush at TripleMania if they asked.
As for PPVs, the best case scenario is them going to Amazon or Hulu and selling individual PPVs in a "on demand" type format at a drastically lower price when compared to the past when Wrestlemanias were $80. Pay $10 for any of the big four, and $5 for any other PPV.
The worst case scenario comes if they go back to a high priced PPV format on cable boxes and removed PPVs from the network entirely. Don't get me wrong, as a wrestler I'd still subscribe to the network, as it is an amazing tool for wrestlers, but as a fan that format wouldn't appeal to me.
In the age of streaming and torrents they'd be crazy to move back to the old PPV model. Due to the time difference I can't watch them until Monday evening, by which time it's already invariably been spoiled, so I wouldn't pay any extra even for the big four. NXT's delayed network slot is annoying as well, since I have to wait until Friday evening to watch it fully.