https://arstechnica.com/gadgets/2023/11/what-to-do-if-your-new-m3-mac-shows-up-with-an-old-non-updatable-macos-version/

Apple’s new M3 Macs are starting to land on doorsteps today, and at least a few people are facing an odd problem: Their Macs are showing up with an old, outdated build of last year’s macOS 13.5 Ventura on them, and checking for updates isn’t giving them the opportunity to update to either the current version of Ventura (13.6) or the recently released macOS Sonoma (14.1).

Affected users have posted complaints on X, formerly Twitter, and places like the MacRumors forums. The unreleased build of Ventura appears to be build 22G80, whereas the officially released version from July 2023 is build 22G74. So far, the issue only seems to affect the basic M3 versions of the MacBook Pro and iMac and not the M3 Pro or M3 Max versions, suggesting that the M3 Macs were ready to go a few months before the more powerful versions.