Earlier quoted context omitted.
Speaking of similar sound system of Finnish and Japenese, I think we should highlight the discredited language family claim of Uralic-Altaic, see https://en.wikipedia.org/wiki/Ural-Altaic_languages You can still find tons of other theories of "what else could be related to Uralic"... So far, no African languages were included in these theories. But that's probably just a question of time and politics (and definitely…
> the discredited language family claim of Uralic-Altaic I'd substitute "doubtful" for "discredited". The article you link says nothing more damning than "It is now generally agreed [wrt Ural-Altaic] that even the Altaic languages [themselves] do not share a common descent: the similarities between Turkic, Mongolic and Tungusic are better explained by diffusion and borrowing", but that wiki comment is a paraphrasal o…
Altaic is a little more complicated, but whatever it is, it doesn’t seem to be a linguistic family tree in the same way that Indo-European is.