A Pixel 4a XL may still be in the works, according to XDA Developers. The website claims to have spotted three new codenames in an AOSP repository, which may point to two new devices and potentially a development board.
https://www.notebookcheck.net/Do-not-discount-the-Pixel-4a-XL-yet-Probable-new-Pixel-codenames-appear-in-AOSP-repository.450480.0.html