Unless a Newfoundlander served in the Canadian Army, I doubt very much Newfoundlanders as a whole would be entitled to the CVSM for as you pointed out, they did not join Confederation until 1949.
Why do you call it a 'spam medal'? Why not call it what it is, the Canadian Volunteer Service Service Medal or CVSM, a medal for those who volunteered for service during the Second World War. I think calling the medal a 'spam medal' is an insult to those who are entitled to wear it. I am sure no-one calls the Aircrew Europe Star the 'I blasted innocent German civilians medal' or the Italy Star 'I boozed my way up Italy medal', right? So why make up silly pet names for these medals?