I received a "B550M DS3H AC" with Rev. 1.5 on 15.9.2023.
I don't remember the BIOS version from back then, I installed the latest version straight away.

I ordered this board from Digitec 2 weeks ago and was able to install a 5600 without an update. I think (don't know) that it would rather need a BIOS downgrade if you want to upgrade to a Ryzen 1XXX or 2XXX... these CPUs are almost antique by now. So if you only have 5XXX Ryzen from 3XXX, I would assume that it works.

Since we purchase the boards from various suppliers, it is unfortunately not possible to ensure with which BIOS version you would receive this. Considering the CPU compatibility, it can be assumed that a BIOS update may be necessary.