I studied Wittgenstein in college, and with enough pot and an undergraduate mind this statement is generally true.
However, I think in this case, Wittgenstein did spell out an early version of the emoticon - emoji maybe a little far. I know my version of the text this is sourced from had emoticon like drawings next to the statement that's quoted in OP's article, but I don't recall if these were added by Wittgenstein or a later editor.
They were Wittgenstein's, the "Letters to C. K. Ogden with Comments on the English Translation of the Tractatus Logico-Philosophicus" includes detailed notes on their typographic treatment.
However, I think in this case, Wittgenstein did spell out an early version of the emoticon - emoji maybe a little far. I know my version of the text this is sourced from had emoticon like drawings next to the statement that's quoted in OP's article, but I don't recall if these were added by Wittgenstein or a later editor.