That's the AR family restriction in a nutshell. You could have an AR-15 with a non-restricted barrel length that meets all the other non-restricted requirements, but it is restricted by name. By the same token, anything other the Valmet rifle derived from the AK-47 is outright prohibited in Canada. Both restrictions have no basis in rationality, but are purely based on the fear of "scary" looking military-esque rifles. That same fear could be turned against the WK, the XCR, et-al, either by name, or by making the gun laws even more restrictive, like California.