Today there is some quite interesting information circulating the web regarding ASUS and its alleged decision. Going a few months back, AMD released a statement regarding the support for its upcoming Ryzen 5000 series CPUs and said that it should enable compatibility with the last-generation X470 and B450 chipset. That, however, has remained a bit of mystery. The update is baked-in with the BIOS, which every manufacturer, like MSI, ASUS, Gigabyte, etc. provides independently of AMD. So it is a manufacturer-dependant case, where if one vendor chooses not to provide support for 400 series chipsets, many motherboards will not support new CPU generation.

Update Oct 14th: ASUS has reached out to us and said that "ASUS will provide updated BIOS' for the X470 and B450 chipsets based on AMD's current release schedule of new AGESA code in January 2021. This original report was based on incorrect information." This means that the customer support case contained wrong information, and ASUS is going to support 5000 series Ryzen CPUs on 400 series chipsets. Please note that the information below is incorrect.This represents the case of what seems to be happening with ASUS. In correspondence with ASUS support, a customer asked ASUS if they plan to update a Crosshair VII Hero X470 motherboard with support for AMD's upcoming Ryzen 5000 series CPUs, the company gave a rather negative answer. Here is the quote below:

ASUS SupportI am writing this email to provide you an update about your ongoing case. According to our engineers, We have no plans for the Crosshair VII Hero to support the Ryzen 5900X, please purchase Crosshair VIII Hero and any Ass (*ASUS) B550 motherboard that will support Ryzen 5900X and 5000 series processors.

You can check out the full Reddit thread here. It appears that ASUS recommends users that they upgrade to new motherboards and that there will be no support of AMD's Ryzen 5000 CPU series on 400 series chipset on their motherboards.