I went ahead and registered for the vault anyway and as you said it was easy enough to get it going. (I'm used to systems failing if you take the initiative.) It would probably be a good idea to get e-mails out to Paypal backers that they can claim their support though.
Larian said that they wanted a "silent start" for the system, I guess in order to test the system with less people.
But I'm quite sure that there will be an update soon which will introduce everyone (PayPal donators included) to the new backer fulfilment system.
