One of the advantages of the new generation of Ryzen third-generation processors is the compatibility with PCI Express 4.0: a faster BUS protocol that paves the way for faster NVMe graphics cards and SSDs. Compatibility with this standard is for the new AM4 X570 motherboards, and until now the motherboard manufacturers had the option of launching BIOS updates for the old boards to make compatibility possible, but AMD has changed its mind.
Although it is technically feasible to enable PCIe 4.0 in previous models (especially the X470 and X370), the requirements in terms of signal strength are so strict that they can not carry the functionality. Therefore, AMD has indicated that this situation can lead to serious confusion, that is working with manufacturers to remove the compatibility. You can read the whole logic of the decision in this thread of Reddit.
If you spent the money on the X470 with the hope of holding a couple of years or more without updating it, this will be a disappointment, but you have remembered that at least you can keep updating your CPU. Apart, today the PCIe BUS is not a bottleneck very relevant to current graphics. On the other hand, if you had already installed a BIOS beta patch to enable PCIe 4.0 on your badge, do not expect anybody to force you to remove it. Of course, maybe the components you install do not work perfectly.