NYC might be in a lead over Shenzhen by 2020. The building cycle is slowing down there. While there are several u/c and proposed, many are sitting dormant. In terms of the rankings, I'm happy for it eclipsing Dubai because I know most of those have high vacancy rates and where built for pride whereas we use economics to build our towers.
I do want to see Chicago move up the rank. Kinda surprised it fell from its stardom in 200m + category. NYC is bound to eclipse its Far East analog Hong Kong in the supertall game. Before the Dubai boom, Hong Kong was the supertall capital. Times have changed in just 10 years. I am though hoping that Americas 2nd city (Chicago) booms like it did before the recession.