This was my experience with early 00s subject-based message boards as well.

It seems to me like Discord provides a similar experience for today's kids. But of course the medium itself is quite different (long-form vs quippy, preserved vs ephemeral) and informs the experience accordingly.

Much as I somewhat romanticize the BBS experience I think it's going to occupy less and less of this type of social space, just by the nature of the way people communicate now.