So they don't believe in Seoul conquering the world one k-pop hit at a time?
Seems like this is based on GDP/population which is not everything though. Washington might not have an as big economy as Tokyo, but it's the head of the world's wealthiest nation, and by far the most powerful military. Also the Bay Area is still pretty huge for tech which is such a big part of everyone's lives these days.
Other important cities that got left out - Delhi, Bangkok, Jakarta, Karachi, Mumbai, Buenos Ares, Cairo, Riyadh (controls much of the energy supply, though maybe not by 2025?). Delhi, Jakarta and Karachi as well as Lagos are all likely to have urban areas of over 30 million people by 2025, along with Shanghai, Tokyo and Pearl River Delta.
Lumping some of these together, like Pearl River Delta seems ok, but Chongqing and Chengdu are separated by 300km, most of which is rural. That's like lumping the Randstadt, Brussels and Rhine-Ruhr into a single region except the areas in between those urban regions are still more built up.