Way too early to tell. As a lifelong Cardinal fan, I am disappointed that this is not taken care of, and AP will be a Cardinal for life. The uncertainty is unsettling.
However, it is a game for recreation for us, it is a business for AP and the Cardinals. I don't really blame either side for the current position. AP has been severely underpaid during this current contract. He feels he should be recognized (paid) for the being the best player in the game. It is a valid point. The Cardinals got a steal. DeWitt was quoted from when the Cardinals were critized for signing him to this contract for overpaying for a young, but still unproven (only three years) player. Asked if he had any concerns about giving AP that contract,"I'm afraid it may not be long enough". The Cardinals do not want to overpay for future, and almost certainly, lower production over an extended contract length.
At this point, I still hope that AP returns to the Cardinals. I think they can justify overpaying now for some of the past years, when looking at overall franchise operations/marketing etc. But they won't be negotiating against themselves when he hits free agency. It is possible that his AAV contract could exceed $30M, because someone else is waving that kind of money around. AP might be disappointed as well, if no other serious bidders materialize, ala Jeter. I believe the Cardinals will make a good offer to keep AP in STL when the market is set after the season.