It depends on what theory it is because plenty of people have made their own theory thread. I don't really go into the KH sections at all and have no reason to since I don't like KH anymore and I don't even have power there so eh.
As for your theory, I think you can be safe with making your own thread. I suggest exploring the forum for a while, reading the FAQ once that's put up again and just seeing how things go if you're that confused.
Or ask me if you have any other questions.