MSI seems to have committed to different support than AMD has. Gamers Nexus has covered the AMD chipset stuff recently to great detail.[0]
There are several issues that come together to make it difficult to support all AM4 CPUs across all the AM4 motherboards. MSI seems to have committed to their AM4 motherboards supporting all AM4 CPUs, and they are having to perform some gyrations (and potentially some reverse-engineering of AMD-supplied binary blobs) to meet their claims.
[0] https://www.youtube.com/watch?v=T5X-8vZtml8&t=0s and https://www.youtube.com/watch?v=JluNkjdpxFo
