I think the answer is "no," and here's why:
I think that shooting forums are valuable as a source of feedback because firearms training is still largely a solo activity. Unless you're lucky enough to have a training partner or coach who is invested enough to provide you training feedback on the regular, you're mostly in it alone. Having a forum where you can go to ask other people for advice can provide that feedback.
For unarmed combatives, the general training modality is to go to a gym with an instructor/coach and drill+spar. The feedback doesn't need to come from the Internet because you have a coach and training partners. Advice on how to pick a good gym is valuable, but I think dedicating a forum to that is a little much; that could be answered in a how-to article.
Also there's way less gear to geek out about. I don't really see a 335-page thread about the Ernie Langdon Edition BJJ gi happening.