I'd be very surprised if it was even that soon. PCIe 3 was delayed as implementers hit snags, it took 7 years between preliminary announcement of PCIe 4 and official ratification and then another 2 years to even show up on a motherboard. As of now, the 2-year old PCIe 5 spec hasn't even reached version 1.
No. PCIe 4.0 is 2 years old. It arrived in 2017. PCIe 5.0 hit 0.9 in January this year, and 1.0 is expected to be finalised in the next few months.
The cycle between 4.0 and 5.0 has been hugely accelerated because there's the need for it in HPC, Server and various industrial applications (i.e. automotive). Plus, stakeholders are generally pulling in the same direction.
Indeed it will be 2021 before PCI-E 5.0 hits HEDT, or Q4 ' 20 if they shift the TR releases.
It's highly improbable that AMD don't do PCIe 5.0 for Zen 3 EPYC. Unless they change what they're doing now, then PCIe 5.0 will necessarily come to TR4, and there's no reason why it would be disabled for AM4 - indeed they need to keep up with Intel who will probably offer it.
But will consumer tech actually utilise the extra bandwidth or is that there initially purely for data centre where they might utilise it?
I remember when SATA 3 had about roughly 4 times the data throughput of consumer HDDs.
But, there may be extra features alongside the extra bandwidth that can be useful for consumers? Thoughts!
PCIe 5.0 delivers significant latency improvements as well as further bandwidth improvements. Hence why 4.0 is pretty much a stopgap. Bandwidth won't do much for consumers over 4.0, but latency certainly will.
Edit: One final thing. I strongly suspect the reason why a lot of the X570 boards have fans on the heatsinks around the PCIe traces is that the intention is that they will support PCIe 5.0 next year. Just as some of the X470 boards are being given a BIOS upgrade to PCIe 4.0 compatibility now. PCIe 5.0 will take the bus speed to 32GHz.