I'm actually very conflicted on where i'd want the server to be if it had to be in any one place(as now) and we got to decide.
Greenland would be my favorite pick in that case, which would mean fast connection for all of US(better than now), all of europe(slightly worse than now) and the countries spanning east, south east and south of europe(slightly worse with the western bank of africa probably seeing almost no change). Australians, japanese and south africans would all get better ping than now(ZA and a lot of Africa actually connect through greenland, not [Northern]europe), NA and SA would not get as good as if it was in new york, but I think the ping curve would be overall great for most countries. The areas where the ping will be terrible are in countries in the west asia area, middle east and most southern parts of south america. Greenland is literally the place where the cross atlantic connection passes through from EU to US(the best one anyway), so having it there would probably be alright.
But still, I think if they got a clear plan to launch a second connected server once they have the income for it(upon release and a successful one with a big population(big enough to maybe even warrant another server in the first place)).Then that will be 100% the best move and outcome we could ask for. We'd have cross continental play, still have the backend to make playing on the opposite "continent" bearable, more of the world have access to even be able to play the game at all and we'd have added stability by having the load distributed over two "servers", one will probably be lopsided and continue to be with wars between the servers, invasions etc etc.