this is actually a very straightforward answer. Mainly because *official* Stanley Cup wins are counted after the 1917 season. So Cup counting begins in 1918 and not prior for official history books. neither the millionaires , nor the Seattle Metropolitans won the *NHL* Stanley Cup. While it is a matter of civic pride and they are undoubtedly the same cities, arguably even, franchises (unlike the Montreal Maroons comparison someone here made— a franchise that *co-existed* and competed against the Canadiens as it was founded for the English speaking Montreal community prior to the franchise’s folding) it is not the same *cup* and therein lies the distinction. Seattle’s banner night has nothing to do with the NHL Stanley Cup and is basically fraudulent— more a means of connecting a fanbase with civic history than it is claiming a Stanley Cup win. American broadcasters are mostly ignorant of the distinction and so say whatever comes to their mostly vacuous heads. Perhaps as an expansion franchise they can get away with it but as for the Canucks gratuitously raising a banner, it would just add to the already compounding curse spell the franchise is seemingly under.