The problem with this entire conversation, as is often the case here, is that we are avid Disney fans. We read these forums, listen to the podcasts, watch the vlogs, and suck in as much Disney info as we can get our hands on. We are tiny fraction of a percentage of Disney World's guests.
Most people simply don't have a clue. A great many people book a trip to WDW and do zero research or planning. Then they show up and haven't got the slightest idea what is happening or what they need to do. They think FastPass is something you have to pay for. They don't understand why they can't have dinner at BOG or why they can't ride Peter Pan. It is beyond their comprehension that they were supposed to make lunch reservations 180 days ago or decide which rides they wanted to get on 60 days ago. The night we had dinner at BOG a few years ago, we were waiting to be let in. A woman walked up and asked how long the wait was to be seated and the CM said, "6 months". Needless to say, the woman was shocked.
Normal people who aren't into this stuff like we are, which is most people, aren't going to buy in to the whole immersion and different language thing. They just aren't. Add in the fact that a great many international travelers come to WDW who already struggle with the language barrier because English isn't their native tongue.
I think in the proper setting, complete story immersion is an amazing thing. One of the most heavily visited theme parks in the world just isn't the proper setting. I agree with Kevin that it won't last. They will do it for a while and then gradually tone it down to a more widely acceptable level as they have at Aulani.
I've done a couple of things over the years where there was immersion involved and everyone had their role to play and it was a ton of fun, but it was on a small scale and it was exactly what we had all signed up for. That just isn't the case here. It's fine if you're into it - go with it and enjoy - but the reality is that 99% of guests won't be.