Absolutely agree. How many times have you heard "that was true until Python 3.4 but now is no longer an issue" or "that expression is illegal for all Pythons below 3.3", and so on. Not to mention the (ongoing) Python 2->3 debacle.
When will this talking point die? It's not "ongoing". There's an overwhelming majority who have adopted Python 3 and a small population of laggards.
That small population includes every BigCo with a large python codebase.