Ive had 1 or 2 of my FT orders magically appear while apparently skipping customs in San Fran. No idea if they missed the scan or what, but no record of it on tracking.
If my theory holds-up, we'll be seeing that phenomenon more often. I suspect that the USPS wants to drive more business to Priority Mail. They're spending lots of money on the advertisements. They realize that businesses are getting free tracking data even when they aren't paying for tracking. So, why would a customer pay extra for tracking if they already get it for free?
The scanning could be happening, but USPS might have created a way to suppress the data from getting posted to the web-portal. In my work experience I've seen companies deliberately delay service when the customer declined to pay for same day service. Even when it would've been easy to just get it done right away.