The F-117 is being retired because it is old, expensive to maintain, and inferior to the JSF. It never had any air-air capability, which was a drawback.
Most programs are generally in the open, with certain aspects kept secret. e.g. the B-2 and F-22. Only a very few become operational without general knowledge, e.g. the U-2 and the F-117.
But its fun to speculate. Perhaps we captured a Klingon cloaking device ;-)
The F-117 is being retired because it is old, expensive to maintain, and inferior to the JSF. It never had any air-air capability, which was a drawback.
***Seems like this would be a good platform to supplement the Close Air Support guys in their Warthogs and/or reconfiguring the plane as an unmanned aerial vehicle to supplement the Global Hawks.