Have to agree with this. LO is a series of measures, not just radar and IR evasion, and when combined with superior networking and situational awareness, will continue to prove viable. On an individual level perhaps LO capability gets degraded but when you bring datalinks and long-range missiles into the equation then detecting platforms one by one becomes less useful as you're going to be taking missile shots from other planes you didn't see as soon as one networked platform becomes aware of you.
I think of it in similar terms when it comes to the F-35's sometimes questioned air-to-air payload of 4x AMRAAMs - while on a platform for platform basis that's a somewhat light loadout, it doesn't take into account the fact that these aircraft will be operating in a network with other fighters and AEW&C platforms means you have to look at the total missile shots available to a package, from multiple platforms. One emitting F-35 could cue missiles from multiple sources and thus the number of available missile shots in the battlespace goes far beyond what a single fighter brings to the table.
As for the LO capabilities, they still interfere with an enemy's ability to detect, fix, and find a firing solution for the platform in question. They can be detected at times, certainly, but detection of a small radar signature doesn't necessarily mean that detection is of a high enough quality to pass to another radar for a firing solution. The whole thing constricts the enemy's OODA loop, leaving them with far less time to detect, compute firing solutions, and so on, before the targeted platform and its mates become aware of the emitting radar and do something JDAMish about it. And your 4.5 generation fighters, with an appropriate weapon system (say JASSM-ER, Storm Shadow, etc), can still hang back at standoff distances and provide strikes based on datalinked targeting information gathered by 5th gen fighters further in.
That's how I see it anyway. There's many different forms of LO that can be taken - we'll see what the future brings.