Is there an expectation that Universal will dramatically raise prices to pay for the third park and the "value" of their offerings is only temporary?
Yeah, but as I was saying, Disney is initiating some of the price increases because they feel that the product is undervalued. Or more generally, that people are willing to pay more for a better experience (less waiting/less planning). Universal wouldn't plan their financial future based on how many people Disney prices out. Universal would be better off accepting their niche place in the market and growing their revenue from the people who are already going to Universal. Their third park is going to increase visits and length of stay for the people they already have coming, not necessarily attract more people from Disney. And to be fair to Universal, that's exactly what I think they're doing.
And again, if Universal was pinning everyone on how many people Disney would drop in the future, Disney could easily destroy their plans just by lowering prices. If price is the one thing determining if someone goes to Universal over Disney, a lower price at Disney would pull people away from Universal, and completely invalidate their need for a third park. Universal would be betting far too much on Disney wanting to shed more of their audience. But again, I don't think that's what is happening.
This has been a common hope on boards like this for a long time. It's been decades now that people were claiming that any year now people would wake up and see that the value was lost at Disney and go elsewhere. And attendance has increased some 50% since then.
Disney is pretty smart at running their business, and if they were in any real danger of losing market share to Universal, they would adjust. It's what they are good at.