Intel is planning for PCIe5 in 2021 (skipping on PCIe4), so AMD having gen 5 support in that generation would not be too unexpected. Though with the seperation

Intel is planning for PCIe5 in 2021 (skipping on PCIe4), so AMD having gen 5 support in that generation would not be too unexpected. Though with the seperation of IO/compute dies I would not be suprised if PCIe5 would only appear in EPYC/Threadripper components. I expect that the upcoming Ryzen socket refresh (AM5, which is expected to come with Zen 4/Ryzen 5xxx) to have support for (or even require) DDR5, as by then DDR5 will already be available for a year.