FOCAL is, but is BASIC? Maybe my memory is just faulty, but I’ve read a fair amount about DTSS, Dartmouth BASIC, and the proliferation of BASICs, and I don’t recall anyone particularly tying them to JOSS. There are certainly similarities, at least in the interaction environment, but the languages share less.
It seems plausible that JOSS could have been known to Kemeny and Kurtz, or their students, but I haven’t seen it discussed or suggested as a direct inspiration.