https://wccftech.com/the-last-of-us-part-ii-companion-and-enemy-ai-to-be-massively-improved-says-developer/

During a recent press event for The Last of Us Part II, Gamespot was able to chat extensively with Naughty Dog’s Anthony Newman, Co-Director on The Last of Us Part II, with regards to the improvements coming to both companion AI and enemy AI. When it comes to the former, companions will be more useful but they’ll also not be often invisible to enemies anymore during stealth approaches.

Companion AI is actually one of the few really significant technical achievements we’ve been able to make on the game. [In the original] there is a mode the AI can be in–which is their default mode when you’re in stealth–where they will just never be seen. They’re almost better than the player can be at being stealthy.