Chinese memory module producer Jiahe Jinwei is among the first to receive DDR5 chip shipments from Micron for implementation. SK Hynix and Samsung are expected to begin shipping their DDR5 chips soon, as well. By the end of 2021, we should be seeing a decent selection of DDR5 modules for the Intel Alder Lake-S processors.
https://www.notebookcheck.net/DDR5-RAM-modules-get-first-green-light-for-mass-production-in-China.530098.0.html