Does Anna Navarre and Gunther Hermann's killswitch codes have any meaning?

Solution 1:

Laputan Machine (source):

• The phrase itself refers to the flying city of Laputa from Jonathan Swift's Gulliver's Travels. In the novel, the Laputans are masters of theoretical engineering but completely lacking in practical mechanical knowledge; the devices they produce are tremendously innovative "on paper" but badly flawed in practice (like Gunther himself).

Flatlander Woman (source):

• Navarre's killphrase, Flatlander Woman, is a reference to the novel Flatland by Edwin A. Abbott, about people living in a two-dimensional world, in which women are just lines. They are invisible when seen edge-on, and dangerous because they are very sharp and can inadvertently cut people in half. The killphrase is a reference to Navarre's cloaking power and her deadliness.