Postfix articles are common in other languages, too (Albanian, Bulgarian, Danish, Icelandic, Turkish...) There are also languages that don't have articles at all (e.g. Czech, Russian, Latin, Finnish, Chinese...).
If we use the metaphor, most programming languages use SVO, not SOV (I'm not sure I've ever seen "instance argument method", but programming languages are weird). Also, in OOP, the method is resolved based on the subject's class, but I'm not sure Basque has different meanings for the same verbs for different classes of nouns (but I can imagine a language like that). Many languages represent linguistic phenomena by different means (e.g. definiteness is expressed by an article in English, by a case in Finnish, by verb conjugation in Hungarian, and by word order in Czech).
Programming languages were created by humans who already knew natural languages. They follow and simplify them, so any similarities are easily explained by similarities between human languages. Claiming Basque to be an OO language is a provoking and interesting idea, but I fear it remains a fantasy.