The map above is not entirely accurate at all times anymore. We did the F!DP on our trip the week before Christmas this past year, and they had moved the reserved seating to the four sections front and center. Anyone without a DP voucher was routed to the extreme left and right, and they did not open the reserved section up to everyone else at all (my husband ran up for snacks about 10 minutes before show time and still had to show our voucher to get back in past the ropes and CMs.
This was of course a very busy time of year, and they had clearly sold more DP's than normal. This was the period when they were trying out the quick service, picnic option as a Fantasmic dining package (a limited experiment they may or may not bring back), and they also had two shows per night. All the DP reserved seating was for the first show, and honestly it looked to us like at least 2/3 of the theater was set aside for reserved seating. We were very thankful we had done the package, and our seats were right up front in the Sorcerer Mickey section. Totally worth it.
One other difference was the entrance - we went to the Beauty & the Beast entrance that the voucher directs you to, and we were met by Cast Members who directed us to go to Tower of Terror, turn in as if we were headed to ride it, and then keep walking around past it; it was up beyond the regular Fantasmic entrance and put us in more toward the center of the theater.
I guess time will tell whether they keep the old model and old reserved sections or if they decide to cash in on selling more DP's at very busy times.