There are indications in forum posts that 2024 has been available via support request for over a year but is still not available via XCTU. 2021 is the latest in both legacy and latest version of XCTU.
Do we all need to create support cases just to get this firmware or can it be made available via XCTU?
2023 is now the latest and greatest firmware version for the XB2B-WF. I think it just updated recently.