The rule for preserving floppies is to not use Windows. Windows is known for automatically writing to disks, so you're not preserving the original anymore, you're preserving the changes that Windows made to the disk.

If you're using Kryoflux or a similar controller solution (and they mention several) it should bypass this problem since then the drive doesn't show up as a normal floppy drive at all. So in this case it shouldn't matter.

Dont most disks have write protection? Would that not be sufficient?

Unfortunately, some USB floppy drives ignore the read-write tab. It's not enforced at the hardware level.