The 1966 original starred George Peppard in the lead role of a German fighter pilot in WWI. The story is set in WWI, but it is actually about the social stratification and norms that existed at that time, namely that the poor were grunts in the trenches while the wealthy were pilots. The Blue Max is about a soldier from a humble background who ascends from the trenches to become a pilot, bringing his perspectives with him. Peppard was a good actor and popular at the time, but not convincing as a German. That may partly be why the social messages of the times were so undersold (another reason may be that the movie assumed that viewers already knew about German social strata).
The remake should feature an actor who is more convincing as a German; maybe it should actually be made in German. The remake should also do more to explain how German (and French, and English) society was stratified at that time. This would provide the context for the accompanying message for who is most expendable, and why. It would also explain why casualties were so high.