Dollars and cents behind it all. We don't see the real cost/benefits, just what we like and don't like. Revamping lost river is a wash for me, but somehow it must be saving them a ton of money. AP might be a cheap ride to keep going at the moment. The squeeky wheel gets the grease as they say.
I think when they release the details on the upgrade, there will be many details as to why..
obviously the new reworked boardwalk
with all the new buildings,
the "new pathway'
the new "lost river",
Although it may not happen, i expect to see a log plume ride of some time in same area, which ulimately will replace AP.
That would open the AP area for the long awaited 3rd coaster in that area, and the opportunity to rework the walkways and paths on that side of the park