I think it does make a difference. Changing the name sends a message from Disney that the mission of World Showcase is no longer "the world". Fiction seeping in here and there corrupts the message, but it does not necessarily kill it. Making the pavilion a fictional land is an official admission that the World Showcase as it was designed is no more, and I don't think there is any coming back from that. To me, changing the name to Arendelle is the equivalent of putting space mountain in the middle of Frontierland. Putting Frozen in Maelstrom and a shop inside the Norway pavilion is like putting Iago and Zazu into the tiki room. Both are disruptions to the theme, but in my opinion, one is a far more unforgivable breach of theme than the other.
I agree, that these are just degrees of the same problem. But in this case, I do think there is meaning in the name.