Hmm, this is an interesting question. It would give other members a window into your writting style, as you say, how you write your chapters and why you do it. It would also give people a way of giving you feedback on what you could improve. However, these questions and such, should already be adressed in the threat with the specific fanfiction.
An example would be the threat "THE LAND BEFORE TIME: JOURNEY TO A NEW WORLD" where one chapter is published at a time, and then reviewed. The review gives you feedback, and you choose wether you want to reply and explain why you did some things, or just nod and agree. It should also be in these threats that you explain things, because, when people read your explanations, then they would (theoretically) have already read your chapters, and then they would be able to formulate proper answers or new questions.
Having a seperate threat about this, would 1) only take up space and 2) be confusing to the peolpe who haven't read your fanfiction and 3) be unnecessary. Personally, I wouldn't recommend having a threat like this.