At it's core that's exactly what both Disney and Norway are doing. This is a business decision, this isn't about staying true to EPCOT, because let's face it, the vision of EPCOT looks nothing what was ever built, this is about selling tickets. Frozen has a huge following, so Disney has chosen to capitalize on it by putting it in a country where it heavily borrowed themes from, depending on what the finished version looks like it's quite possible that replacing Maelstrom with a Frozen themed ride is the most economically viable choice. It'll draw crowds, it'll sell tickets, it'll sell merchandise, and the eternal optimist in me hopes that some of that revenue equates into more attractions being updated/built. I've always loved the Norway pavillion, but to me Maelstrom is a mediocre ride at best. Often times I would skip it if the lines were on the longer side, in the summer I'll take it just to get out of the heat for a few minutes.
A few years ago I decided I wanted to take a trip to Norway, I had a trip coming up to WDW so I made a point to stop by the Norway pavillion. You know where I learned the most about the country? Not from taking a 5 minute ride, but by actually talking to the Norwegians who worked there. They were incredibly helpful in helping me plan my entire itinerary. At the end of the day EPCOT is a theme park, change is going to happen, I may not love the idea of a Frozen attraction, but I understand the reasons why, and I'll reserve judgement until it's finished and I get to experience it for myself.
