Comment 1 for bug 1454457

No update is presented to you because the update is still being phased to all users. It will become available to you some time over the next 24 hours.

However, the fact that the update was *previously* presented to you (with less than ideal results), but is now *not* presented to you, implies that your system's identifier has changed across reinstalls. My recollection is that the system UUID is intended to be derived from the hardware address, so should not change on reinstall. That much is definitely a bug.