The only response would be that an editor (at some point) would review the site and decide whether or not to list it. Editors are strongly advised not to e-mail submitters. And editors who have previously ignored that advice are generally eager to explain to new editors why it is such good advice.
How would a review go?
For a "chat and forum" type site, the editor will be asking "is the forum active? (if not, no listing.) Then are there already active forums that cover this subject, and if so, does this forum have anything to offset the enormous disadvantages of splitting the conversants in a niche online community, or is the community large enough to support multiple forums? (again, if not, surfers are better off patronizing one active forum).
A forum without a core is just an echo chamber. A core could be either a community that already carried on a significant amount of communication, for which the forum becomes the vehicle (as this forum and ODP editors), or it could be a "content-rich" website strong enough to attract visitors by its non-interactive content (such as the old searchengineforums.com, an offshoot of jimworld.com, one man's online business presence).
But a forum, like all aggregate-content-type sites, is not easy to jump-start. And -- this is important to understand -- the ODP is specifically there to not help the jump-start. An ODP listing is not a tool for achieving success, but a recognition of success achieved -- where "success" mean only one thing: "content worth recommending to surfers".
(There are obviously other measures of success, but they typically are uninteresting or invisible to ODP editors and other surfers.)
