SnowKomodo
Deity
The main arguments for Indonesia are:
1. Lots of support over a long period
2. No new civs added in Asia yet
3. Would fit new features well
4. Huge modern population and potential market
We'll see what happens though. I pretty much expect they'll be in at this point, but who knows.
For #3, one thing that gets lost on people is how significant a role Indonesia played during the Cold War scare. Despite their history of trade and diplomacy, they had their bumps along the way
For #4, the huge market extends beyond Indonesia into Malaysia and Singapore. These ASEAN emerging economies bode well for Civ sales for Firaxis if not already now, then at least by Civ 6 and 7