To be honest we haven't figured that out yet after we switched to the new forum solution.
I know that the forum software by itself does not allow to delete your own account by default, and it has to go through an administrator of the forum. So that seems like a pretty reasonable approach to this request.
However, deleting also posts seems to me to go a step too far. The posts you participated in may then become completely useless, if some critical information is then missing suddenly. Imagine the disappointment if you search for a solution to a problem, and then you encounter a forum post that says "thanks, that was the solution!" and the actual solution was deleted.
We can probably accommodate anonymizing something very specific, like if a post has something sensitive in it, like for example if you accidentally posted some private key or address or something specific and sensitive like that. But otherwise I think we'd like to keep at least the posts themselves in the forum, to preserve its usefulness.
By deleting your account though, the post content would be retained, but it would not be linked to you anymore. it would state as author something like "deleted" - so it would become anonymized in that sense.
I will discuss it with the community to see what policy we want to adopt for these kinds of requests and update here.