Two days ago, the build number was 24B83, and now it's 24B2083, yet software updates don't see 24B2083 as the latest download.
macOS 15.1 Build Number 24B2083 or 24B83
Build Number 24B2083 is for M4 Mac model.
That's far from the truth. I was running macOS 15.1 24B83 as a guest OS on an M2 Max Host. The guest OS updated to the 24B2083 seed from 24B83 seed.