As someone who still might have a '2023 take on LLMs', even though I use them often at work, where would you recommend I look to learn more about what a '2025 LLM' is, and how they operate differently?
Don't bother. This bubble will pop in two years, you don't want to look back on your old comments in shame in three.
Papers on mechanistic interpratability and representation engineering, e.g. from Anthropic would be a good start.