Definitely no, lots of weapons systems were never used in combat

One glaring example would be B-58 Hustler. This bomber was operational in USAF, fortunately never used in war (as it was designed as nuclear bomber), but unfortunately killed some people while it was tested by company test pilot and flight engineer. So people died while producing it. B-58 has been retired a long time ago, so chances it would participate in some war are almost non-existent.

Another bomber that participated in war but didn't directly kill anyone was B-47 Stratojet. There arewere lot of systems from Cold War that were never used, and industrial and testing accidents involving this plane, including deadly accidents with factory test pilots. It did happenparticipate in Vietnam war, but only as reconnaissance and ELINT aircraft. It is also retired so its production did kill more people then its use .