Agree with others that it's a wait and see situation. Even deeper, it depends on what type of gamer you are.
I have seen a number of people who insist on 4k/60 non-VRR gaming. Which is .. something, I guess. In those cases, I don't think it much matters between Ryzen 5 1600, Core i5-8400, etc, all the way to 3900X/9900KF. You're going to be screaming at your 2080ti or Titan RTX to please keep up, lol.
However, at 1440 in 16:9 and 21:9 + 100/120/144Hz, THAT is where the extra CPU juice pays off IF you have the GPU to also show gains. In my case, 1080ti Aorus with 8086k OC, I choose to scale graphical options and AA down a bit (especially shadows, which I never notice that much in motion), in order to maintain very high framerates. This is why after testing back and forth I use the 8086k over the 2700X box, it just has that extra 10-20% to work with.
Honestly I think best case is that it's something of a wash. Which would be honestly a gigantic achievement. Because gaming was THE reason to go Intel for the longest time now. The Ryzen 1000 and 2000 series were already either equal or better, sometimes by a notable margin, in basically everything else. But honestly gaming was a pretty sizable gap there.
In many cases, this was never going to be that noticeable, such as my example above of the 4k/60 folks. Similarly true of someone running 1050ti / RX570 / 1660 @ 1080p. Just not going to see the difference between the CPUs with that level of GPU bottleneck. Still, I always like to think of the future, and people tend to keep a mobo/CPU much longer than a GPU if they're a gamer, so if say by 2022 you have your i5-8600k box and a Ryzen 5-2600X box, and both are max OC, and you can get ~2080ti performance for $199 and that's your next GPU, then indeed, the 8600k @ 5Ghz will probably be better than a max OC 2600X. Ryzen 3000 series SHOULD change this to : basically equal, while superior in most other things.
But we are definitely not the prime candidates for such things at present. As cool as it is, it's more of a sidegrade in all probability for edge cases like ours. Though if we were building in July 2019, of course the 3800/3900 look a lot more compelling I think.