Earlier quoted context omitted.
.app, .dev, .prod, and .zip all had substantial volume of problematic traffic that was discovered during the Controlled Interruption period (which occurs prior to launch and consists of a wildcard DNS entry placed on the entire TLD). You would not believe some of the brokenness that was happening there. .zip may need some explanation -- apparently there are lots of library API calls out there that take a path string…
ICANN should never have assigned .zip, there's just too much potential for abuse, confusion giving away a common extension as a TLD.
Besides, accidentally resolving a file extension to a TLD is only one of many possible different serious errors that can result from exposing an API that can load files locally or remotely, and thus make network calls that you might not be expecting. Fundamentally you need to fix that API either way.