With Google I/O 2020 canceled entirely, there was some uncertainty around the Google Pixel 4a series' release date. Internal documents sourced from Vodafone Germany indicate that Google's upcoming Pixel 4a will hit the shelves on May 22nd. General availability could vary a little, depending on your location.
https://www.notebookcheck.net/Google-Pixel-4a-slated-for-a-late-May-release-according-to-leaked-documents.463251.0.html