Buyer deleted their account?

I was in talks with a buyer on shipping two items they had bought from me. The items are shipped and on their way to the buyer. Never heard much after sending shipping detail and such. Later come to find they delete their account. Should I be worried. Should I try and cancel the shipment? The funds are currently on hold until the shipment is finalized. Im just worried the buyer might somehow pull a fast one and cancel or issue a refund when receiving the items.

Note this is my first time selling on eBay still figuring out how this process all works.