From this poll ( https://forum.defcon.org/showthread.php?t=14027 ) the preference is to open DEF CON 23 forums starting in September.

Of course, half as many people voted for the option to make baby kittens cry, or "never" because "DEF CON is cancelled" but that does not matter.

You want it early, ok then!

Will be rolling out contest forums for DC23, for those that announced plans to return in this thread:
https://forum.defcon.org/showthread.php?t=14003

If you have a NEW contest, event social gathering or village, you will have to wait until the RFI for your thing is announced, and approved before getting a forum to match it.
Also, as stated in the above thread, early forums are created under condition that organizers submit their thing and get it approved. Forums follow decisions of departments that have resources to offer organizers, so forums will conform to their decisions.

If you want to "go rogue" and take on risk of doing something outside of DEF CON, I won't stop you from posting threads unless they are violations of our other rules (Politics, Religion, Spam, Illegal, etc.) but dedicated forums for contests, events, social getherings and villages are limited to those that have some kind of approval from the department with the resources for whichever is to be run.