The 30 days you must wait before submitting a tracking request is roughly the same amount of time they take to decide that your parcel is "unclaimed" and is now THEIR property to dispose of as they see fit, typically in the form of auctions. I bought an item twice from eBay because of this.
The item was shipped by a seller from Slovakia, and stopped having tracking updates after clearing New York customs 10 days later. Seller was not able to initiate tracking until the parcel had disappeared for a month, by which point I received the detached shipping label from the original parcel, with a hand-scribbled note explaining that it was found by itself at a USPS sorting hub here in California. There was no way of knowing at which point during the many transfers between NY and CA this label and its parcel parted company.
As I now had proof that the parcel was missing, I was able to file a "missing parcel inquiry" at my end online, which entitled me to a monthly form letter informing me that they were "still working very hard looking for the parcel".
My local post master tried to put me directly in touch with the sorting facility that sent me the disembodied shipping label, but they told her they are not allowed to talk to non-employees.
My post master also revealed that label-less parcels are deemed "unclaimed" and shipped to a warehouse in Georgia for disposal. If no one came forward to claim and prove ownership for 30 days, the orphaned parcel would be auctioned off or destroyed. My missing parcel inquiry contained detailed item descriptions and the listing photos from eBay, but since the item was inside a box, which was presumably still intact, it was very unlikely that anyone at the Georgia warehouse would have opened up all the label-less boxes to look for it before it's bundled up for auction.
As it were, my missing item showed up on eBay right around the time (according to its listing date) I was running around in circles with USPS looking for it, though I didn't realize this until I accidentally came across the second listing 4 months later, as it never occurred to me that this was a possible outcome. The seller was in Tennessee, and listed many things that could have come from government auctions, though I have no way of knowing this for certain and wasn't going to ask him. His starting price was way high, as he probably had no idea what the item was worth; which was why it was still there 4 months later.
I updated my Missing Parcel Inquiry with links to this eBay listing, showing that it's the exact same item (as it happens to have a serial number, visible in both sets of listing photos), hoping that USPS could give me some explanation as to how my item went from their sorting center to a seller in Tennessee, with only the shipping label coming to me.
It had zero effect on their search or their communication. I continued to receive the "we are still working very hard looking for your package" form letter for two more months, fulfilling the six month obligation specified in their regulatory requirement, ending with a final letter saying exactly what I had come to expect: "Sorry, we can't find your package in spite of our best efforts. Have a nice life".
Eight months after the Tennessee seller put the item up for sale again, his asking price was reduced to just slightly more than what I had paid the Slovakian seller 10 months earlier; so I bought the item, again; this time without undue drama. The item was noticeably more scuffed up than it was in the original Slovakian listing photos, so there was some physical trauma involved along the way.
The lesson I took from this: Never count on a shipping label taped to the box - Write the recipient and destination address directly on the box, even when a shipping label is used!!