I noticed that in the thread between the worlds, the other worlds are floating in bubbles. In mooshu, marleybone was in a bubble. In marleybone, Aquila was in a bubble. In Aquila? KROKOTOPIA!!!
Just because they mention a world doesn't mean were going there but its still a good chance it will come. The only time a mention of a world means were going is like things like at the end of book 14 and a particular cat tells us some important information or when rooke says he has urgent business in marleybone.
I believe the worlds we see while traveling along a spiral thread is more indicative of which worlds are located near that spiral thread, or near to the world we are traveling to, rather than which world will be coming next.
It's a way of KI giving a physical representation of where each world actually lies within the spiral.