The USAF has stated it has no plans for the Silent Eagle it's aim is the F35A Lightning 2, Even With the Congressional Raptor hunt leaving the F22 as a Endanger species Lightnings are intended too be the American mainstay which will leave some thing of a major hole in the USAF and force the continued use of F15C/D.
On a personal note I don't think "Silent" fighters really fit the generation 5 definition and prefer too think of them as more of a gen 4.75.
For stuff like Silent Eagle, I fail to see how much more lethal it can be. There are some things with a ceiling to it, and platforms like the Eagle, for that matter, can never be truly stealthy no matter how "silent" you make it, from adding RAM and such. The reason is cause not only its design wasn't bent for reduced RCS from the beginning, but also its features and curvature and what not, will always be what's holding the Eagles back, and it will continue to do so until they are improvised. But doing so is almost completely developing a new airframe.
In addition, it's been officially settled that the Eagle's agility is as good as it can get with its current airframe design, therefore unless they install a TVC like in the F-15STD, in the battlefield it will still have to resort to BVR engagements and avoid WVR. A2A-wise, the Eagle is still an Eagle, therefore in WVR A2A, it is a very weak competitor in the contemporary era of Eurofighters, Rafale, Flankers, etc.