Not having seen the alternative it's hard to say exactly, but the proposal sounds more or less a refreshed status quo solution save, perhaps, for the theatre. In that context, an alternative pitch to demolish the building and remake/open up the whole central spine area, including with Journey Into Water (which this thread is ostensibly about) and a new multi-storey festival center/roof-top restaurant with space for entertainment underneath as the focal point and big revenue generator, does sound more ambitious.
People here have talked about the possibility for rooftop bars, dark rides, etc. for that building, but it doesn't seem any of that was in what WDI pitched to management for keeping the building. This doesn't mean the proposal that won out was ultimately better, but if the teams pitching competing plans for refreshing Epcot were told to think big, I can understand why management would have looked at more meet and greets, food and beverage, a theatre, and exhibition space with the central spine remaining more or less the same as not quite fitting the brief. More space and more cover is a pitch, but it's not a particularly exciting one.