The important factor is not just whether you have a forum, a single thread, or whatever.... it's a question of how frequently you actually update and add content. If you have a mod team, you can appoint someone to take care of this as a 'publicist', but if you are a small team, or one man operation, where do you find the time?

If a mod is active, then their forum thread should stay visible and at the top.

Personally, I think the burden of a forum al lyour own would outweigh the benefits for most mods. Should be judgement call of the Mod Leader really....with a reality check from the hoster! Where things go silly, IMHO, is when the mod teams start setting up tiny forums all over the place, where no-one visits, and only a handful register. No-one posts, no-one cares.

Forums should be granted to mods on the basis of activity in their own threads. Not their own posts....but those of others showing an interest!