One of the most useful elements of GA was you need which provinces the computer would fight to the death for and never surrender...

I do miss GA mode, but seeing as they never got it 100% functional it is not surprizing it is absent from RTW...

Finally as the Wonders are prebuilt, what GA's could you have?? Trade, Homelands and Conquest.... The trade ones were always a bit dodgy anyway so that just leaves Homelands and Conquest which is pretty much what we have got...