How would the presence of super-powered beings, magic, aliens, etc. affected this moment in history? Would it have been the same? Would things have been different? Can this question be answered?
Frankly,it depends on the power of the heroes in question. Few heroes of the era were quite as powerful as they would become later.
It also depends on how the powers are distributed, and how cost effective mass production is (generally answer is "Not Cost Effective).
I've been working in a low powered world setting where supers DID take part in WWII. The result being that WWII ends as normal, but Hitler and his occult madmen go underground and continue to fight a secret war until his death in 1954. The Nazi's remain alive and even more devlishly secretive and continue to pop up even into the 21st century, but never as a world power--only as a terrorist group.
But that's the only difference the intervention of the Supers and Paranormals does to the War.
It's sort of the Hitler Time Travel Excemption Act for Supers.