Aside from the fact that "blitzkrieg" never existed in the way people commonly assume, ie it was never called that and there wasn't really anything new about how the Germans were conducting themselves, there are numerous issues with those assertions.

For one thing, John Monash is NOT the father of combined arms tactics. The British, French and Germans had already utilized these methods before on the Western Front and elsewhere, as at Morval, the Ancre, Vimy and Messines Ridge, Hill 70, Caporetto, Riga, and Malmaison. His attack at Hamel was a great success, but it's value was only as a tactical success; wider, operational level consequences were only achieved by applying combined arms methods on a much larger scale, as at Amiens weeks later.

Secondly, the Australians did not "end" the "blitzkrieg" at Tobruk. Logistics halted Rommel and the Italians advance there, but many more sweeping armoured victories were to be achieved by German and Italian forces in North Africa. The first real check of the "Blitzkrieg" came between October and December 1941 in the Soviet Union, and it was first really defeated at Kursk in July-August 1943.