Understandable 
Just for the sake of knowing, I went ahead and did a test for you. I made a post on a character to establish a post history - the character had already visited the forums a few days and was first seen on the 24th of January. Here is the post:
Then, I (only) name changed the character. No other service, just name change. This is that character, and you can take a look at the forum profile and see it is trust 0 and this post I am making right now will be its only post. So what I was saying appears to be correct - changing the name-server will give you a new forum profile.
Hope this helps.