[alt text: a semi-surreal meme image on a plain white background. Two characters from Dark Souls are saying, "My lord, we have absolutely ESSENTIAL lore information for the player. Should we make a cutscrene for it?". They are looking at Hidetaka Miyazaki, who has the From Software logo emblazoned over him, and he is replying, "NO...Put it in the description of a COOKBOOK". There are several cookbook item icons floating between the characters.]
I think they just mean that it's not necessary for playing the game. It isn't like if you know the lore then you can find a secret cave, that gives you access to extra content. It is there for its own sake.
The value add that it gives is entirely dependent on the individual. It would be nice if there was some gameplay reward for reading it.