Not sure if TylerDurden was getting at whether the track and train will be visible from other parts of the park permanently, or whether it will be visible between now and whenever they decide to officially announce this thing.
Personally, I don't think it would be a problem for it to be seen incidentally from other parts of the park once it's open and into the future. But if they plan to have as much testing time as a lot of people on here have suggested, it'll be quite a leap for people not to notice a steam engine floating around behind the buildings.
The general public might catch on to what's happening; not just us nerd-folk.