I have seen potato pancakes described as Jewish, but the other two are so inherently Hebraic that they don't need the additional specifier. Like you don't have to prefix "British" on Bubble and Squeak or Spotted Dick. You just know they're the fault of the Brits and leave it at that.

German Potato Salad doesn't pull any punches. You know you're getting the full fat yumminess of oil and bacon in every bite. That one needs the specifier, because it's warning you of the lack of Mayonnaise, which is, of course, an evil French invention for sticking foods together.

there's non-jewish potato pancake?!

...also there's an ungoing argument if falafel is jewish or lebanonese.

my bet is that they invented the stuffing for something else and jews where the ones who thought "you know what's missing? a ton of oil"... possibly around chanuka.

It's a pretty widely distributed variant -- it's hardly the light-colored yellow version of potato salad without boiled egg in it. Sliced hardboiled egg or not is just an option.

The German potato salad with the red potatoes and vinaigrette and herbs is a different potato salad.