So sad to hear about this … it means that we probably won’t be seeing any mini-ITX motherboards using the X670 chipset.
Taken from TPU … As we approach the next generation of AMD’s Ryzen processors, accompanying chipsets will follow the launch of their main co-host device. Enabling different levels of features across the new processor generation, chipset versions are limiting the number of options a platform offers to the end-user. AMD is designing its motherboard chipsets in collaboration with a Taiwanese design firm ASMedia. They usually develop a few chipset types covering low-end, middle-end, and high-end motherboards segments. However, it seems like the high-end motherboard segment could be populated with the same silicon as the middle-end section of the chipset stack; note a few Chinese forum members on BiliBili.
As they note, the high-end AMD X670 chipset could be a multi-chip module (MCM) design incorporating two middle-end B650 chipsets. A combination of two B650 dies is allegedly forming an X670 chipset, and that is what AMD could force motherboard makers to use. By doing so, the Mini-ITX motherboard form factor could be challenging to design and manufacture, meaning that the package of the X670 chipset could be rather extensive. This rumor should, of course, be taken with a massive grain of salt as we don’t know how this would function. However, it financially makes sense as AMD wouldn’t need to design and request manufacturing for an additional chipset variant.