They more than likely will NOT delete you account. The reason being is that it either will leave a missing post every place that you posted or that they can not do it with out searching for each and every post and deleting each one. I would suggest that you leave your posts as is as I am sure that many of them contain some good info for others to follow. You can cancel all your subscribed threads and set your account to NOT receive pm's or emails. And you may want to change the email account listed in your account to something like 123 @ not yahoo.com without the spaces of course. Then you could not be contacted.
edited for worse than normal grammer