I also wonder if some deprecated practises and packages will linger in the training data for a long time. I remember the Python 2 to 3 transition. A lot of people parroted all kinds of outdated information on Python 3 and that made people hesitant to switch to Python 3.
I found it amusing I used to push Rust so many years ago not knowing that I’d eventually get everything I asked for. And especially not how it would happen.
Just like many open source maintainers lectured their unhappy users that their broken and featureless software was given for free and they should make PRs instead of complaining.
Be careful what you wish for, etc
This is wrong. Training data is almost irrelevant because LLMs can apply cross-language semantic understanding. JS training data applies equally to JS, TS, C or Haskell.
Tooling and libraries matter much more than semantics for language use, and training data is crucial for that