I both agree and disagree.
If you have a catastrophic acute failure, you're unlikley to discover it in a UOA because of the sudden nature of the event. If a con-rod breaks, or piston skirt shatters, you'll only know it when the unholy noise comes knocking (paron the pun). Other failures, chronic ones, will give some notice. And if you have the right info at the right time, you actually would see the issue in a UOA.
Also, the nature of the failure plays into this. If you crack a con-rod, while there will be some small particles shed, most will be very large parts flying apart. Fractures happen nearly instantly in terms of failure, and "chunks" are the prominent result (these chunks are far to large to be seen in spectral analysis). Wear-related failures are different; they will shed plenty of particles that can easily be seen in a spectral analysis.
The greatest inhibitor to seeing a cam/lifter failure in this case (modern Hemi), is that our sense of "timeliness" is unlikely to take the UOA sample(s) at the right time. If you only UOA every 5k or 10k miles, the failure mode can initiate and ramp up quicker than those limits. If you were to UOA every 1k miles, you quite possibly would discover the issue at onset. Also, to see this in a sense of relative trend shift, you'd have to know the exact variation of your wear pre-event, so that you can recognize the Fe uptick as it begins a trend-shift. As I understand it, these cam/lifter failures occur when the roller bearings seize. From there, it doesn't take long to destroy the lifter and the lobe. Plenty of YT vids to show this being the case. It may not be the only failure mode for this problem, but it's certainly the prevelant one. There's no way you'd miss the onset of failure IF you were taking UOA samples often enough, and had the specific statistical info needed for your particular engine. But because most folks don't have this info, it goes "unseen".
My point is this ...
It's not that a UOA can't catch this type of failure mode; it certainly can. The issue is that you're unlikely to see it simply because you're not looking often enough. The UOA technology, in and of itself, is certainly capable of detecting the rise in Fe. If this Hemi failure mode took 30k miles to gradually increase, pretty much anyone would see it taking UOAs every 10k miles. But because it happens most likely in 1-3k miles, pretty much no one will every catch it until it's too late.