a Ryzen 9 3900X that peaks at 4.5GHz instead of 4.6GHz is only missing out on 2% of its total possible boost clock rate, and even that 2% clock rate does not generally translate to 2% slower application performance. In other words, you're going to need artificial tests to discover the problem—you absolutely would not just suddenly realize, "hey, this isn't as fast as it ought to be!" in the middle of a gaming or content creation session."
I'm not saying this isn't something AMD should fix up... if for nothing else to avoid stupid law suits. Its just such a non story, makes me almost hope AMD does just bring back PR numbers. It would be so much easier to just say this is our 12 core 5000+ and this is our 8 core 4600+ and avoid sillyness. Of course having this stuff end up in an Intel marketing PowerPoint is pretty damn funny.