Always available for edits? Editing a NW post after someone has replied to it is against the rules so I see no point there. As for village threads, you can always get a mod to edit the required post. Generally only things like village rules or positions would get updated but even then not too often.
NW and Village threads are similar to the battle arena, you don't need infinite edits unlike the CJ threads. They only got infinite edits to prevent a new thread being made every few weeks.
Besides all this I am curious as to why you'd want this ability for NW threads?