That automated 1* feedback only happens when the order gets into “Very Late” status. The seller should have contacted you for a time extension before that happened.
As a buyer, it happened to me, or rather, the seller I bought a gig from, only once - and apparently, the seller had just abandoned her Fiverr business, never delivered, never reacted to messages. Finally, I accepted the cancellation offered by the automated Fiverr system, to get my refund.
You, as a buyer, aren’t able to keep that automatic 1* review from showing up in that case and it was your seller’s responsibility to either deliver timely or ask for a time extension, so you shouldn’t worry about it too much.
Fiverr also sends sellers a reminder when their orders get near due date.
It’s a part of Fiverr’s quality assurance system, like a penalty for sellers who neither stick to their deadlines nor ask the buyer for a time extension - which would be the thing to do if they get sick or whatever and can’t make it.
Here’s a link in case you want to post it to your seller (who, by the way, is only asking for more trouble if they harass you about that):
You should do your best to deliver on time. Plan your work accordingly and make sure your delivery time is realistic. When an order is very late, it will automatically be canceled resulting in negative feedback. There are cases where sellers will deliver incomplete work to avoid being late, and this behavior is unacceptable. Sending a delivery to avoid being late is a violation of Fiverr’s Terms of Service and could result in your account being reviewed. Fiverr encourages sellers to deliver on time. However, if it’s not possible, then we recommend using the extended delivery time option offered in the Resolution Center.