Normal for Microsoft and Windows 10.
I have posted, on many occasions, that the "major updates," by which I mean updates which change your Windows 10 Version Number, do not roll out like regular Windows Updates that apply patches or "small functionality" to a version already on a given machine.
Regular updates to existing versions tend to roll out over a period of days, at most. Major updates routinely roll out over a period of months. Machines are grouped into update cohorts (and how Microsoft determines when any given machine running Windows 10 ends up in one is a complete mystery) and the individual cohort is updated. That cohort's telemetry is then monitored to determine whether any unanticipated issues occur and whether any of these need to be fixed before the next cohort is formed and the update applied to it.
That's one of the true beauties of the ongoing use of and improvement to system health telemetry. Given the sheer number of machines out there that have been upgraded to Windows 10, many of which were never certified by their makers as being Windows 10 compatible, it is absolutely impossible for Microsoft to have a test bed that would include anything close to all the configurations out there running Windows 10. If a major "burp" is encountered on any significant number of machines, and particularly if those machines do not share a common platform, then fixes to whatever causes that "burp" must be done before roll out continues. If a major "burp" occurs on some hardware that is not officially supported, then there is still the question as to whether other hardware that is might be using the same component(s) that are triggering the issue(s) and whether fixes still must be applied before roll out continues.
I have two of my three machines, both Windows 10 Home, 64-bit, that have been upgraded to Version 1703 and those two updates were months apart. My Windows 10 Pro 32-bit box still remains on Version 1607, and I have no idea when it will be added to an update cohort for Version 1703. I just wait. The only time I would worry is if/when Microsoft announces that the roll out for a given Version is complete and I have a machine that did not update via Windows Update for some reason. Then, and only then, would I consider using the Media Creation Tool to do the upgrade manually.
Brian AKA Bri the Tech Guy (website in my user profile) - Windows 10 Home, 64-Bit, Version 1803, Build 17134
. . . the presumption of innocence, while essential in the legal realm, does not mean the elimination of common sense outside it. The willing suspension of disbelief has its limits, or should.
~ Ruth Marcus, November 10, 2017, in Washington Post article, Bannon is right: It’s no coincidence The Post broke the Moore story