A fun issue I keep hitting with Github Copilot in Python is that it's a coin flip whether it will give me a Python 3-style print statement or a Python 2.7 style print statement.
You raise a fascinating point about older platforms of other languages, too; Java has a super backward compat story, but woe be unto the coder who tries to name a variable "enum" nowadays
For me, it sounds like it's closer to dumb copy paste than a smart code generator. AlphaZero wouldn't play a chess move that was against the rules.