PCIE5 standard is finalized, and one of the controller chips is scheduled for mass production in 2020. It is unknown if it will be adopted by any PC platform, but if console holders want it, they could have worked to get it.I don't really believe PCIe 5.0 will be ready for consumer products next year. They say they producing it next year, but 4.0 only came out this year desktops. Is there any reason 5.0 would be adopted way faster?
edit - some info directly from PCI-SIG