I would guess, that what we'll see more than anything at the world showcase is more food/beverage purchase options. Whether they've lucked into or not, they are surely aware of what epcot has become. The food and wine festival, and the flower and Garden festival, focus a great deal of energy on making sure stomach's are satisfied. Now it's somewhat at odds with the meal plan. Apps are not part of the meal plan. People love to eat and drink. If people won't drink their way around the world, they'll snack their way around. That is real money in their pocket. Add gift shops that have a bit more variety than the average stuff on property, and you have a huge profit center.
That being said, wdw is family oriented. You need to keep the children occupied to Mom and Dad can fill their face. I think you can expect kiddie rides and dark rides in the world showcase going forward. Something the kids can do while the parents enjoy "a foreign country", or as good as it will get for parents recover from sending little johnny to college and hit retirement.
If you follow the revenue opportunities, Epcot has huge potential. They may have lucked into, but I think they are realizing that it is a great opportunity.
I have to believe the my magic system finally gives the suits a true picture of where their money is being made, and they are now finally free to spend where they think it will contribute to a return.
WS doesn't need a million rides, but it sure could use at least one more near the IG somewhere. Need not be an amazing new experience.
I think your formula for any new country is going to be like the mexican pavilion. A dark ride, a couple of restaurants, a fun lounge/bar, somewhat unique gift shop, and quick serve karts. If they care about the eats, they'll have to pick a country that makes sense. I haven't gone out for Egyptian food lately, Greek food could be good, Brazilian that could be good. Swiss, could be good but I think Germany may have stolen that thunder. Russia, no thanks. Caribbean Island food, sure. Australia...maybe. Spain or Portugal, ok. India, sure.
If you are looking for return on investment, I think that is the way you have to look at it. Find where the bean counters and imagineers can find middle ground.