I think Samsung doesn't really announce it because the DAC differs between the Snapdragon and Exynos models. I know back in the S7 days they did, with the Exynos models getting the better DAC. However, Samsung does have Adapt Sound to make up for it. If you take the time to set it up, it makes worlds of difference in the music quality through headphones.
Oh, nothing from Samsung had ever existed YET to rival the V20, let alone the V30. Samsung's software solution, while excellent, can't equal dedicated hardware. Again though, if you never bothered to setup adapt sound, then you're missing out on the true music capabilities of a Samsung device. It's not something you turn on and it's there. It takes a bit of setup. You need to go into the music quality settings and let it go through the audiometry test before it works. The biggest difference I got from it was when it turned the sound output if cheap 10USD headphones to rival 30-40USD ones that weren't set to Adapt Sound.Well, I'll tell you this. I had the S7 edge and an Axon7 that had a 24bit with dolby atmos. The A7 put the S7 edge to shame. They weren't even in the same ballpark. That's why I went with the LG V30. It truly beats all others, especially with a great set of phones and buds. The point I'm trying to make is that if manufacturers announces what things are going into their devices ahead of time, I may have waited for the S9. Provided it has a hifi dac. But I'm more than happy with the V30. So far, best phone I've ever owned.