“If the seller uses a tracked postal service, surely that will be all they need to confirm delivery, and not have to rely on the buyer doing it.”
That may well be the case, we don’t know until the new procedure is in operation. I may be wrong, but as I read it the buyer will have to positively confirm delivery because the item may have been delivered to another address and signed for by a recipient. This happened to me when a courier delivered an item in error to a house almost opposite my property. The householder signed for the delivery, even though it had my correct name and address on the package, but couldn’t be bothered to point it out to the driver or walk over the road to tell me, some people! After several days of phone calls and emails the courier identified the error, went back to the property, collected the package and walked the 30yards over to my house with it.
Plus, I am sure we all know of people who hardly ever go online except to carry out their immediate task and then don’t go near their computer, even to check for any emails, for days or even weeks in some cases. If, having received their purchase, they then don’t follow the procedure by positively confirming delivery the seller is going to be left in limbo. If somebody doesn’t go back online to check their messages they will not see any reminders from both the online auction site or the seller asking them to confirm delivery. We will have to wait and see how the new procedure pans out.