I think our government is getting comfortable talking about stealth technology. Lazar talked of a reserve of new tech being worked on. Seems reasonable to me that they would be willing to disclose stealth information if they had something else in the works.
I think it is very likely that they would have something more in the works that on occasion gets spotted. Our military has already stated that they work at night on new technology just to keep it hard to spot and identify. Not to mention the work of keeping secret that such a tech could exist.
While it is still top secret, our government is still willing to mention that the B-2 Stealth Bomber uses electro-magnetic additions on the front of the wings. The stated reason is to add more air flow so that the plane can stay up with less work from the engines. Thus less heat to be detected with.
Even the Raptor can "hover" if only for a short amount of time through what they refer to as "vector control" on it's tail.
It was 50 years to go from propellers to jet engines. Already we see they some very talented tricks can be pulled off with the aide of other newer tech to push jet engines to new limits. I have not doubt that new methods of flight that could never be taken seriously before now are coming into being.