The reason we ask for your address is that sometimes we cannot reach you through your email address because of spam filters or for some other reason so we may have to write to you via the post office.
Once, again, one more way to contact you if it is neccessary with more information. The WFA will never contact you for any other reason.
Do you happen to have a website where you have put information that might help us better understand what you do know?
What ever it is that you do know can be very helpful.