The spring update was a press release and then I think based on Twitter posts, only Tesla-info actually had it on cars they track and they published the actual release notes which were then copied by Notateslaapp. There have also been individuals posting videos of it in use. Teslafi seem to get the latest info later and later nowadays, since the shift to the new fleet API so I certainly wouldn’t assume because they don’t have it means it’s not out.
Tesla typically (and sensibly) release to a small number of users and then wait to let the dust settle, depending on whether there are issues or not they’ll either extend the roll out or have to bug fix and re-release to a small number again. I wouldn’t be surprised if we don’t hear from 2024.12.1 release or more cars getting it in the next 24 hours.