I had some input from the guys on here when I was considering the recent 5900X and GB B550 board that were for sale on the BST. I drove myself nuts doing research on the USB issues. In the end I decided not to upgrade, but not really for that issue. More just because I didn't "need" (whatever that means...) it right now and couldn't convince myself to just buy it for fun!
In my research there are still some USB issues out there but AMD believes the fix is included in the latest AGESA and many people, even with complex USB device set ups, have had the issue resolved by updating to their motherboard's latest BIOS with the new AGESA.
It caused me a little pause for sure because I run a lot of flight sim gear from USB, and an DAC/AMP. Random disconnects in any of those devices would drive me bonkers. But in my research it seems a very high likelihood that the problem has been resolved.
Also you have lots of comments here saying they haven't seen the issue at all so that helps!
In addition even if you do run into the issue there are workarounds online for how to resolve it but some of them involved disabling PCIe 4 or similar fixes.