Maybe, but the underlying reasons for WW2 still existed (and indeed it had started by that time). Would Goering or Himmler have taken over and done things differently? Perhaps the allies would have sued for peace, perhaps the invasion of France would wait until the smoke cleared and a new leader is in place, with the same army and increased internal pressures. Would that new leader invade the Soviet union before pacifying the UK. Would a delay in invading France have led to FDR not standing in 1940? There's all sorts of posibilities, but it doesn't feel as major a change as some other fateful decisions - the broad strokes wouldn't have changed.
An intriguing possibility is that the execution backfires because the Nazi leadership had a war to inspire the public so they didn't really need Hitler, and could make much smarter decisions in his absence, and so the Nazis actually win the war (or at least achieve a settlement in a much smaller war which leaves them still in power). But I guess it's also possible the leading Nazis fight each other like rats in a sack over who takes over, who was to blame for the assassination, what military action to pursue next and why were they going to war alongside the hated communists against everyone else in Europe in the first place, and the whole thing falls apart very quickly.
"Nazi leadership had a war to inspire the public so they didn't really need Hitler, and could make much smarter decisions in his absence, and so the Nazis actually win the war "
Since fanatism and not smartness were the desired traits in the Nazis, I doubt they would have made more smart decisions - rather infighting with the national conservative part of the Wehrmacht and society taking over. (thanking the nazis for the plain power base they build them and getting rid of democracy and then kicking them out, like they planned from the beginning and reinstall a king)
Well, we will never know, but I think it is very likely to have had a huge impact. All sorts of outcomes are possible, from internal Nazi power struggles, leading to more moderate forces taking over and making peace with the west and later in a new alliance against russia, or simply consolidating Nazi germany as a mid european superpower between soviets and the western alliance.
