I work the tower/RATCF at KNFW. I guess I had no idea because nearly every squadron at our base does visuals inbound, and not once has approach ever called us to ask if they landed or cancelled.We have 7 satellites with instrument approaches, and many more one could do a Visual Approach into. If I have multiple aircraft on approaches to a satellite I tell the first one it's important they cancel IFR ASAP. Until I have cancellation from #1, I put #2 in holding or issue vectors to burn time.
On several occasions AC #1 didn't cancel in the air and Flight Service has no cancellation either. Now we have to call the airport and try to get someone to see if that AC is on the ground or whatever before letting #2 land.
I've never had one go far enough past the INREQ or ALNOT phase to affect me before finding someone on the ground to verify the AC landed.