The USPS/UPS/FedEx/Amazon etc scam texts are 100% random in their timing & targets. They have no connection or correlation with any genuine, active orders/shipments one may have placed with a vendor, website, or store.
Typically scam texts are sent out en masse. The scam just preys upon the potential that any random recipient may have an active number & may have a curious/fearful/rushed reaction that will open the way towards compromise.
(Sometimes the goal is just to test if a phone number is active, with a bonus of confirming the target is uninformed (vulnerable) about scams.)