Ah! I forgot how long the land clearing took and just remember 2-3 years for a build.
ALso, My thing is a lot of people that do take vacations to the parks utilize a lot of social media and read/look at blogs. All they have to do is type universal orlando and plenty articles and pictures come up about the new ride. They KNOW something is coming by the sheer amount of coverage people give it for free so if that doesn't stop them from still coming then i'm sure an announcement wouldn't. Although I, personally, feel an announcement closer to opening is better.