Since you asked for comments: i see nothing wrong with your speculation about what is possibile now. 
Look at the number of registered users (especially recently registered users) and see how few of them have been posting until now - things could well develop along the lines you suggest.
I think so, too. The new BBS will develop its own tone and the tone of this one will likely change somewhat. And the corner pub may also be there for years to come.
(I very much suspect that i am not the only one who conveniently uses different BBSs to express different parts of their personality or experiment with different personas. 
In any case, there is something that i think happens in online commuties exactly as in real life communities: some people get somewhat stuck in a certain behaviour pattern that relates to the reputation they have built up in their community, and when they move into a different community they feel free to behave in different ways and create a different reputation.)
EDIT (later addition): Here is recent example of the kinds of threads that seem to illustrate Jaboney’s point: Stuck
Another (less recent) example i could cite were the (now disappeared) threads started by the Lithuanian rainbow woman.
I don’t feel anybody contributing to the thread i am linking to here as an example has said anything inappropriate as such, yet i think posters like the OP won’t come back, because young people who sign up to this BBS in the hope to get some advice concerning what they see as a problem they are facing (even assuming for a moment that “we” don’t share their perspective) don’t need a bunch of older people getting in their face and telling them to shape up (they’ve already heard that, that’s why they’re reaching out this way for advice). A question i’d like to see discussed on this BBS is whether “we” care about young people and other newcomers coming on board or whether “we” prefer this to be an in-crowd BBS?
(Should this go into a different thread?)