A handful of new AMD chipset names surfaced in USB-IF registrations. AMD denies that the entries are legitimate, but well the names are in there alright. You will notice a Z490 and X499, which have been rumored about a couple of months ago as well. A420 is also listed, the successor of A320.

The Z490 chipset would enter the race as the new flagship in the middle class, already ready and scheduled for the start of the Computex 2018, but literally, five minutes before the show was still pulled: Too expensive and supposedly too few new features, it was rumored. Additional PCIe lanes would be accomplished with an expensive PLX Chip, which was not available in sufficient quantities, reports computerbase. The same applies to the X499 chipset for the high-end segment. This apparently also was already at Computex 2018 as a refresher for the Threadripper 2000 is considered, the latest rumors now say that he could be unveiled at CES 2019 .

In addition, there is also an A420 chipset as heir to the entry-level model A320. The A320 has not appeared anywhere yet, as have the Pro 460 and Pro 490 solutions - presumably the business offshoot for the Ryzen Pro processor line. 

AMD has commented on the topic, and they normally do not talk about unannounced products.

USB-IF certification is a standard procedure for all chipset development, planned early in product development. The USB-IF site was recently updated with AMD test chips which have not been and may not be released. We are working with USB-IF to have these erroneous listings removed from their site.

AMD

The list is real though:

New AMD chipsets surface at USB-IF: A420, Z490 and X499