> there are languages with a relatively small number of distinct syllables, like Japanese
Japanese has around 50 syllabic symbols, depending on how you count - include both sets of kana? include more archaic kana? etc
What would be a more typical number of syllabic symbols? I tried googling it to get an idea, but couldn't find much useful information. I guess Arabic has 28?
I think they meant syllables specifically, not syllabic symbols. Meanings syllabic symbols might get confused for an alphabet if the language has a sufficiently small set of syllables. See https://linguistics.stackexchange.com/a/36909