Regardless of behavior of the pax, if the LH employee used the word Jew, that's crossing a line. Especially given they are the German flag carrier. They should have just described them as "non-mask wearing pax" and leave "Jew" out of it!
If Black pax misbehaved on DL in ATL, and they used the word black it would also be bad PR for the same reason -- past historical sensitivities!