RF4 - It doesn't make stealth obsolete.
However, it does make it more challenging than it was in the F-117 days, where you could get away with worrying about monostatic radars (transmitter and receiver in the same place), most of them operating in the above-UHF/microwave bands.
What it may mean is (1) that the difference between broadband/all-aspect LO, which really drives towards a tailless blended-body, and the evolved F-117/22/35 approach becomes more important and (2) that stealth still needs to be combined with other techniques and systems - tactics, standoff, EW &c.