From the same piece, this paragraph makes it sound like Italian is the working language of encyclicals (albeit not definitively). Bolding mine:
Whereas a hundred years ago the Latin version was produced first and then the vernaculars were rendered as translations of it, now the Latin version is the last to be completed and is essentially a fine-tuned and carefully raked Latin translation of the Italian.
From the same piece, this paragraph makes it sound like Italian is the working language of encyclicals (albeit not definitively). Bolding mine: