So your talking about a few star wars movies ?
Seriously Disney made 3B at the box office last year and could hit 2.5B again this year. Those movies also drive sales of cheap plastic toys and of course cheap plastic bluray discs and digital downloads. Disney is making money hand over fist and the parks are also doing really well at this point in time.
Also like the majority of projects they most likely already had the funding on the side ahead of time. I would imagine that DHS expansion was already paid for before ground was broken.
The way to look at it is this way , this decade all the parks received major upgrades or will be upgraded. Fantasy land expansion , Avatar , toy story /star wars and whatever epcot gets. From here on our if Disney is smart they just need to rehab older rides and perhaps add 1 to 2 rides a decade to the parks. We got to the problem of Hollywood and Epcot because they didn't add new stuff for a long time. Hollywood has basicly decayed since what ... RR or Tower ? What was the last big ride they got ? Even star tours was just a refurb of a ride. They can't let that happen again. They need to stay up on the parks making smaller investments more often instead of doing these large massive make overs. They will simply be less disruptive . Until toy story and star wars opens no one I know is planning to head to Hollywood studios and for the few who might go , its to hit it early in the morning do the 3 rides worth doing and heading to another park. They need to avoid something like that in the future.