Well, it not only predicted it would be a 'core part' but it's pretty explicit about 'everyone is connected' and the disintegration of the border between real life and the 'wired' (ie: no one is really anonymous - except Lain at the end when she erases her past and history) - this is a pretty unlikely idea at the time before facebook and the rest of the dataminers.
There is also creepy gender roles pressuring, including sexual, and alienation going on, not to mention the suicides and hikikomori tendencies, different 'roles' for different audiences, etc. Only really needs a #metoo and some fascism and racism there.
It's not really surprising considering the author being a fan of psychological horror. Reality seems to have a darkest timeline bias. Anyway, it's a important cultural artifact.