It's already there.
If the simple fix to PI's decline was to return it to being a ticketed "attraction,"
why didn't Disney (who knows that strategy inside and out)
do that years ago?
Well, "here is why" (it's been stated ad-naseum before, but we'll go through it yet again

): Disney finally realized the basic premise of the value proposition (centralized "adult" fun -- ergo,
a nightclub district on property) had been deeply,
deeply flawed from the get-go.
How so? Simple: PI
never got critical paying traffic mass when it was ticketed -
because not enough resort guests had so-called "adult fun" as a primary WDW priority.
Heck, I remember my first visit to PI in 1992. I was at WDW for a conference, and one of the sponsors had rented the entire island for the better part of a weekday evening. I was told by one of their staff that night that "
we got a deal on the rental because Disney is having a tough time building traffic here." That sounded surprising then, but in retrospect it was a clear early warning signal that foretold where things were going to end up.
And opening the floodgates (ergo, removing admission and allowing everyone and anyone in) only exacerbated things.
Bottom line - most people who spend four figures on a WDW trip don't have "adult fun" on the agenda. The minority that do generally don't define said "adult fun" as hanging with downscale Gen Y mall refugees who are playing tag with armed cops.
But that's what the typical PI experience had become and Disney was smart enough to finally decide to stop the brand damage.
As for the residual elements of local-yokel teen pollution at places like Virgin and AMC, that's what unfortunately happens when you dilute a unique, speciality retail environment with generic mall-level "entertainment" properties. Replace 'em with pricey niche retail or dining and the riff-raff will go away.