I agree but it depends on what they are using the number for. The Nvidia developer carrier board seems to have designed 20.3W as the module max and that, and the other values, seem to grant a comfortable margin for the module if one was designing a carrier board for the device.
For determining estimated/min/max battery life, actually testing a device and not use theoretical numbers would be more useful. Similarly, to determine power requirements for a farm of them, it would be better to actually test. There will be differences if Wifi is utilized or not, etc. as you mention. What the board pulls really depends on what it is doing and what mode it has been set to.
If someone asked me what min/max to design for module power on a custom carrier, I’d say 0W (power off) to 20.3W (maximum with slop) would be reasonable. If they wanted to go tighter than that range or determine average for some scenario, I’d suggest they test it.