Both DE-CIX and AMS-IX have exchanges in NYC now. Both have actually started branching out and building exchanges in many new cities. The traffic levels they're talking about are specific to both of their home markets (Amsterdam/Frankfurt).

DE-CIX has the same "metro" setup as AMS-IX as well, they're in a large number of locations https://www.de-cix.net/products-services/de-cix-frankfurt/ in the Frankfurt metro area.