It only means you won't be able to use coinwarps in the hub. If I've got it right, you can still use coinwarps in other levels, and it will still save your coin count when you get back. Could be wrong, mind you, but I think that's how it works. Gah, indecisiveness.

EDIT:
Okay, checked with JCS, and coins do not work. Triggers seem to, on the other hand. So perhaps the system's structure could be something along the lines of this:
http://www.mediafire.com/?ipb0o67kcrfynm3