I have tried 2 different RPI I/O boards and get the same result from running rpiboot
pi@Section9:~/usbboot $ sudo ./rpiboot
[sudo] password for pi:
RPIBOOT: build-date Apr 30 2023 version 20221215~105525 21ba5119
Waiting for BCM2835/6/7/2711...
Loading embedded: bootcode4.bin
Sending bootcode.bin
Successful read 4 bytes
Waiting for BCM2835/6/7/2711...
Loading embedded: bootcode4.bin
Loading embedded: bootcode4.bin
Second stage boot server
Cannot open file config.txt
Cannot open file pieeprom.sig
Loading embedded: start4.elf
File read: start4.elf
Cannot open file fixup4.dat
Second stage boot server done
the CM4 does not show up as a USB MSD at all from Windows, or NIX DMESG shows the following 89.543462] usb 1-1.3: USB disconnect, device number 3
[ 91.216870] usb 1-1.3: new high-speed USB device number 5 using xhci_hcd
[ 91.317486] usb 1-1.3: New USB device found, idVendor=0a5c, idProduct=2711, bcdDevice= 0.00
[ 91.317506] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=4
[ 91.317512] usb 1-1.3: Product: BCM2711 Boot
[ 91.317516] usb 1-1.3: Manufacturer: Broadcom
[ 91.317521] usb 1-1.3: SerialNumber: cab56164
[ 92.931013] usb 1-1.3: USB disconnect, device number 5
[ 105.684946] usb 1-1.3: new high-speed USB device number 6 using xhci_hcd
[ 409.841791] v3d fec00000.v3d: MMU error from client CLE (4) at 0x4aa1000, pte invalidAs usual with everyone else that has this issue, when booting the CM4 off a SD card it runs just dandy but when it comes to flashing it..... not so much
Yes it can. It doesn't have to, but we like to install our OS for testing purposes.