Why would he not be allowed to make a thread. I planned to make one too. Getting a tad more feedback won't harm anyone, I thought
Maybe forum masters or organization makers can clarify the allowance
A lot of people tend not to because they want to keep their concept ideas to themselves.
A mini contest usually involves a single spark of inspiration and applying it to a limited space. You then get several map threads of promising concepts; then another gets submitted on the deadline incorporating several of the previous fresh ideas complimented with their own, and then winning because it's appearence is superior. An entry which may or not have won were it not for the influence of the WIP threads for other entries.
Whilst it provides a potentially more awesome winning entry, it's a little unfair to contestants during the contest when an approach by 1 contestant improves anothers. From a community perspective, ultimately any fresh approaches to detailing will all be published on submission day and available there after for use by designers; from the contest perspective it improves the overall quality of entries. To me it seems fairer when there is less influence on an individuals concept, which is fundimentally what should be marked:- an individuals original concept and personal execution. It seems silly to limit peoples potential for concept development... but it seems fair under the circumstances to do so locally.
Tactically, since it really only takes 1 idea to create a control point/fill a 2048x2048 space, it's usually beneficial in a competitive sense to keep it to yourself, like a trump card. Even if potentially the end results aren't as impressive if everyone were to take that stance and limit creativity. It does feel like something that should be a constant though, rather than a variable. So people are less likely to go into contests with sneaky tactics. It's not like there aren't plenty of opportunities for concept development outside of the immediate community, were it to be that mini-contest WIP threads become prohibited.
Edit: Sorry for OT post, Kiwi