They'll definitely need to diversify there too
If you look at the other SWPs they are in fact diversifying a little bit (Catapult Falls, Serengeti Flyer) so it's definitely not that they're turned off to the idea
Personally, I think it's smart to build up their coaster line up pre-Epic. Which will open with four coasters, five if you count both sides of the celestial coaster
I also believe SW is in a good spot with its current aquarium and show offerings
Some friends that visited recently didn't do any coasters but really enjoyed the animal things, Sesame, as well as Infinity Falls