Thinking they said something like the JSA was a secret organization. Not well known at the time, and not hidden from history but mostly just a footnote. Steel's grandson mentions there are pictures of his grandfather online if you know where to look. Stargirl and Obsidian are the only ones with noticable super powers. Vixen and Mid-Nite's powers are subtle and would just come across as highly trained humans, as would all the non-powered members (not sure if that version of Steel had the metal skeleton but it's not obvious either way).
The break for me was that they were all the modern versions of the characters in 1942 rather than the originals from the 40s (for the characters who existed in the 40s or later creations officially retconned into the JSA of the 40s)
A little hypocritical of Vixen telling Ray he's not a superhero because he relies on gadgets. She relies on an artifact, same thing. As soon as the Nazi's take away the totem, she's sitting in a chair until someone saves her. Ray doesn't stop when someone takes the suit.
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