And human communication is in part down because people have taken it to the forums. Even if just 20% of the stuff posted in locals previous can be directed back into the game again, that will noticeably increase the number of messages posted there, which in turn might bring people like you to add to it again, increasing communication in-game further.
This is an unprovable assumption. I don't think that the forum is even remotely the cause of the problem you've identified; if anything, it is only a symptom of the real problem, which is low player density.
There's just not enough players in most realms these days to generate the same vibrant levels of interaction that you see on the forum and that you used to see when average realms had 50+ characters each. You need a certain number of active players to generate self-sustaining interactions. Most realms don't meet that threshold any more, meaning that driving interaction has become a chore for the few players left who are active in each realm. It's like having a conversation with someone that only replies in one-word answers; it gets very draining after a while to keep the conversation going, so eventually you just stop talking and suffer the silence.
All the forum does is stand in stark contrast to the game in this respect. It may be tempting to blame it for the problem since it's doing so much better, but it's not the cause. It's just one of the few places left where generating BM-related interaction is a pleasure, not a chore.
