Can this diary teach us anything about slang used during wwii?

The diary of Anne Frank? Yes. We heard the names used for Jews and other people or things several times.

Their hunting ground for new terms is in their native tongue as well as foreign. They adopt traditional devices of similitude, making attributes work for the whole. They use hidden resemblances, they know no limitations and have no boundaries. They have substituted far-fetched figures for a hundred literary descriptions, using abbreviations most freely, compositions, formations of words to resemble the sound and picturesque synonyms. Their transfer of proper names into common usage has been so much “duck-soup” (that which is done with ease)…They have enriched the national vocabulary with many new verbs and verb phrases. It must not be forgotten that our fighting men have come from all walks of life, that all sections and divisions of a free social order are represented and each man has brought the peculiar and colorful language of his section of the country with him. Ours is a fighting force of a hundred races and as many creeds speaking a language called American.”