The OP's main question in that thread is: 'For the moment I assume you get DBP from ghosts only when you defend your own siege. Is this true?'
However, no one actually says 'yes' in the answers or anything which suggests such. Only answers along the lines of: 'You don't get any BP for supporting ghosts' and stuff which don't answer the question like 'You get BP for atking ghosts' and 'You can attack your own siege in ghosts'...
Anyone reading the thread would presume the answer is 'no' to the main question from these answers.