Well, we all might have a sentimental attachment to the original Tiki Room show, but I don't think Tokyo Disneyland's has that "classic" status that the Disneyland and Walt Disnwy World versions had. To me, it seems like the attractions don't have as passionate a following as the characters and entertainment. So, if something is changed out at TDL, it doesn't appear to cause a vocal reaction.
I'm not even going to attempt to bash the Stitch addition to the show though, because I have no idea what the final product will be. I did like "Get the Fever", and I'll reserve judgement on the new show until it's open. I do have to say that Stitch is kind of an inspired idea for an addition though. Of all of the attractions to put him in, the Tiki room is the best fit. Sure, he's an alien, so obviously found a home at WDW's Tomorrowland, but the whole Hawaiian aspect of the film just lends itself so well to blending with the Tiki Room. I can't wait to see what they did with him!