Following the official announcement of the full line of Ryzen 5000 processors on October 8, there has been some controversy surrounding the compatibility of 400 series chipset motherboards with these new processors.
While AMD has said that the 400 series boards would be compatible with Ryzen 5000 processors, it is dependent on a BIOS update from the manufacturers. And, due to circumstances with ASUS motherboards in which it seemed that this update was not going to be possible, now they are beginning to receive official announcements from the motherboard manufacturers specifying whether they will have an update or not.
MSI, without going any further, has said that it will have BIOS updates for all 400 series motherboards in January 2021, including the X470 and B450, whether they are MAX or non-MAX. The boards of the 300 series such as the X370, B350 and A320 would not be contemplated in principle, although according to AMD it would not be impossible. That MSI decides to release updates later is something that will have to be seen in due course.