The current answers on Definite/indefinite articles vs. inflections agree that (definite) articles are acquired by languages, not lost.
I'm wondering what Eastern Aramaic has to say about this. Semitic nouns can be in the absolute (default) or the construct state (for genitive constructions). Aramaic develops an emphatic state to mark definiteness. However, in Eastern Aramaic this emphatic state becomes the default, so the definite article effectively gets lost. This is, at least, how I interpret Gzella (A Cultural History of Aramaic, 2015, p. 28):
The “absolute” state (or “unbound form”) acts as the unmarked form; when the emphatic state emerged as a postpositive definite article, the absolute state came to signal indefiniteness. It is generally used with the quantifier /koll/ ‘all’, adverbial and numerical constructions, and predicative adjectives. Morphological definiteness marking spread gradually during the opening centuries of the first millennium b.c.e., following a common tendency in Northwest Semitic, but the “emphatic state” lost this function in later Eastern Aramaic (for instance in Syriac) again and became the unmarked form, whereas new definiteness markers then evolved from demonstratives in Neo-Aramaic languages.
Is "(definite) articles are acquired, not lost" a universal, or should I read the linked question in the context of Indo-European only?