They have already hinted at this model with single ride LL and honestly, as much as I hate it, I find myself buying into the pay to pass the line model. For my family its already over $1,500 per day of Disney vacation when you take into account food and lodging. If you told me for a mere 20% more wait times would be under an hour for everything (honestly I do enjoy a 30 minute que experience in the modern ques), I'd sign up for that model and not think twice.
The crux of the issue is that while the parks can theoretically handle X people, the optimal park experience is at 60% of X. So you either get there via a reservation system, or price increase. Price increase fattens the bottom line, so that's what they'll do.