Hopefully, sellers realise that they have to do this - it really has nothing to do with Simple Delivery - even before Simple Delivery, if you accepted a return and the label was generated through Ebay, the details were taken from the seller's information.
Worth pointing out though, for anybody reading this, when you move house you need to update all of your addresses. You have to repeat the same action five times to change all of the addresses Ebay has on record.
"There are two ways to be fooled. One is to believe what isn't true; the other is to refuse to believe what is true.”
Søren Kierkegaard, Danish philosopher (1813 - 1855)