Update: They actually do. I clean slated the entire task, from the server to resetting the nameservers on the domain host - and it worked. Not sure what happened, but it's also a solid reason to copy and rename files on the server before editing them (I use filename.ext_BAK), so you can start fresh without the hassle of trying to recover settings.

NOTE: In practice, I discourage this outside of personal projects since there's much more to an NS than simply registering it. It is, however, good to learn.