How could you even hide a coaster of that scale for four years, even if it wasn't built in the end? Who would buy it without building it? Where do you store it? Kingda Ka has almost a kilometer of track, and probably twice that in supports. Way too much to store indoors, but outdoors it would surely be noticed. I mean, areal imagery of the area is widely available, it's
here on Google Maps, imaged in high enough detail that you may see single persons walking around (at least you can spot their shadows). If a kilometer's worth of track and supports were lying around, wouldn't somebody have seen it by now? You can see the parts of the Mack hyper clearly enough, so a Strata coaster's worth of track would be plainly visible too.
Based on the amount of unclear communication about the GCI coaster (once rumoured to be the longest coaster in the world), I'm going to guess that the person who spoke to Ben had misunderstood. The track was either for something else, or it never existed at all. A Kingda Ka breaker would be too difficult to hide for so long.