No, not exactly. When you are not depressing the gas pedal, and the engine is revving above a certain speed the momentum of the car is keeping the engine at that speed, and not the fuel injected into the cylinders. The computer then determines that the engine doesn't need fuel, and will stop injection. Exactly what speed that may be remains unknown to me, but my driving instructor back in Austria told me above 2500 rpm. I think this may be closer to 1500rpm for this engine - hard to tell. Here's a link to technical information on all the great little things Honda did to improve the engine's economy AND performance.
Honda Media Newsroom Release: 2006 Honda Civic Powertrains
Throttle-by-wire means that there is no mechanical linkage between the gas pedal and the throttle body anymore. Your gas pedal position is interpreted and a certain behavior is enacted on the engine. VTEC on or off, will some of the volume "inhaled" by the cylinder be ejected again before it is combusted, etc etc. The technical document was very insightful! (The "regular" 1.8 engine info is toward the bottom of the page.)