Very good question. I don't think it would cause overcrowding, although it might at first (since it's been a long, long time since Disneyland prices were that low, and you'd likely see a flood of people who haven't been to the park in many years). Once the prices stabilized, though, given that AP price increases would cause a decrease in AP purchases, I think you'd see less overcrowding, especially given the fact that you have an entire second park available.
Originally Posted by gatheringrosebuds
The primary reason the park is crowded so often, honestly, is because AP prices have been kept so low for so long. As I was growing up, an AP wasn't even offered. You paid daily to get in, no matter whether you were a SoCal local or a tourist from the other side of the planet. And you know what? Crowding, and certainly overcrowding, was never really an issue, except during certain major holidays like Memorial Day, the 4th of July, Labor Day, and Christmas.
This article supports my argument that it's the AP prices that cause locals to visit the park so frequently (and thus cause overcrowding).
Disney Raises SoCal Annual Pass Prices 30% - to Keep Locals 'Out' - Technorati Business
Annual pass holders tend to be local residents of southern California who love the parks. But local residents don’t use the hotels, buy the merchandise, pay for expensive dinners, or fund any of the other merchandising or services that tourists do. Quite simply: Disney makes a lot more money on tourists than “locals,” so they’re pricing the park passes to keep locals away.
Not only do locals not buy nearly as much additional merchandise and services as tourists; but lots of locals in the parks make them more crowded, and actually discourage more tourists from visiting. So, Disney is using the classic laws of “supply and demand” to discourage people from buying the annual passes; thus making the parks better “tourist” destinations.
While I agree that AP prices should increase, I don't think that locals should be "kept away." Locals should be able to visit the parks, affordably, whenever they can, even if it's not QUITE as often as they would with an AP. I think if AP prices are to increase, then single and multi-day ticket prices should decrease as a result. That's only fair.