A third (and potentially 4th) track and a third (and potentially 4th) theater are bandaids. But Bandaids do serve a purpose. We know that Star Wars expansion is happening, the problem is the time frame (5 years). At Epcot, we anticipate a Frozen attraction is coming, as are potentially other additions. I would expect Frozen and Soarin' Over the world to be online at around the same time.
Increasing capacity at high demand attractions is a good thing, we just want to see it done in conjunction with new experiences. At Epcot there are new experiences coming with the capacity changes. At Hollywood Studios, those new experiences are likely coming after.
So, assuming that capacity increases are happening, we have to look at the motivation. We can look at guest satisfaction as a reason, and that's all well and good, but it's not guest satisfaction by itself. It's guest satisfaction as it relates to Fastpass+ and Next Gen. Look at the most frequent complaints about Next Gen:
- We don't like planning in advance
- We don't like how Fastpass+ reservations aren't available day of
- The tiers are confusing
- We like being able to switch to popular attractions if our plans change
Adding capacity to the two most popular attractions in the parks helps with all of these. Sure there will still be problems like Test Track, Seven Dwarfs Mine Train, and Frozen in Norway, but expanding Soarin' and Toy Story will likely be enough to eliminate tiers and give more flexibility. It's digging deeper into the Next Gen problem (which was flawed from the beginning), but it's a way in Disney's mind to "make it work". The other way of course, is to also add new attractions.