I will echo what David said. So far, I have only seen 1 TechTuber report stability issues, but I haven't watched a ton of videos yet. I do not know if stability problems are a widespread issue. For my testing, I had absolutely no stability problems with the 9700X and 9600X. I actually tried 2 different BIOS's on the ROG CROSSHAIR X670E HERO I'm using, first, the official public BIOS from ASUS prior to the launch, which was version 2124 dated 7/19, this BIOS is based on AGESA Combo AM5 PI 1.2.0.0a. I had no problems at all with the 9700X on this BIOS. Second, I updated to BIOS 2201 provided by AMD, it is still based on Combo AM5 PI 1.2.0.0a but adds a PatchA for improvements with 12c and 16c Zen 5 CPUs, that's the only difference in that BIOS, but I also had no problems with that. Right now, ASUS has an even newer one on their website, 2204, but I have not used it yet, it only became available on the 5th, and it says the exact same Combo AM5 PI 1.2.0.0a PatchA version as the one AMD sent.
David hit the nail on the head with FCLK. It is possible some might experience issues on certain CPUs/RAM/Mobo combos with a higher 2100MHz (or higher) FCLK (Infinity Fabric). The "sweet spot/safe spot" for stability is 2000MHz. In the one video I saw, of the tech tuber having stability issues, they did manually set it to 2000MHz. So beyond that, I don't know what else would case stability issues. But, surely you may see some differences in both performance benchmarks, and stability, based on the motherboard/RAM a reviewer is using for reviews, so as I stated in our YouTube video, make sure to always check the Test Setup page for any review you read online, to see what they are running.
For me, and the hardware I'm using, this launch was super smooth. The only thing that I questioned was the performance I experienced, I felt it to be below expectations, therefore I exchanged a lot of messages back and forth with AMD to share my concerns, and experiences and compare benchmarking performance. AMD actually re-ran several benchmarks in their labs, of what I was using, so we could compare notes and validate performance. There was a good interaction there with AMD, and AMD was very tentative about my experiences in regards to the performance that I experienced.