I don't think it doesn't make sense to already have the film done. I'm just filling in the blanks and assuming that this columnist has good sources. If he doesn't, then none of this matters. If he does though, this is what I imagine.
Disney has always had plans to sometime update the film in Epcot. They've also got a greenlit plan to bring Soarin to Paris sometime in the future. The easiest thing to do is to make the same film for both of them. So they shoot the film of Soarin over the world. Now saying that it's in the can could have many meanings. It could just meant that the principal shots are complete but they all still have to be edited. Who knows how long that takes with this type film.
So, possibly the plan will be to unveil the new film as part of Epcots 25th birthday. That would be either late 2007 or early 2008 depending on when they unveil it. Then when they're ready to spend the money to build the ride system in Paris use the same film there. It wouldn't make any less sense to unveil the film in US a year or two before Paris. Especially since they've already done that with unveiling Californias version several years before Epcot got it. (If I'm remembering correctly).
How many visitors to Paris's park actually come to the states to Epcot. So the chance of the film being old hat to them because they've already seen it in Epcot would be slim.
Now I could just be going out on a limb here, but if this guys sources are correct, then it's fairly simple to just fill in the blanks as I have. I'm not saying I have any sources or this is what will happen, it just seems like it would make sense to do it that way. The only differences they'd need would be if they want to keep the Magic Kingdom shots at the ends of the ride. They'd just have to have one for Florida and one for Paris. Not much difference in the video and relatively easy to do.