I think you should ask directly on the sub forum why they are a different forum. It may not actually make any difference.
EDIT: In looking a the Resorts Board. The main board (Disney Resorts) is more of a planning, asking questions about the various resorts place. And the community board (Resorts Community) is a place for general discussion of experiences, posting photos of stays, etc.
But, as you noticed, the lines are bit blurred. I'm sure if you posted in the "wrong" place (not that there is really a wrong place) you'd be directed where to get your answers.