Especially these major updates are pushed out in stages. I don’t know what the criteria are, but for me it feels like it is by chance, so sometimes you get the update over the updater immediately, sometimes you’ll have to wait some days or mostly weeks, sometimes until the next point release.
You’ll see above in this thread, that you can’t affect (or not that I know of), weather you get the update in the stable channel or not.
But, there is a little workaround: In the days of the major update, the beta channel contains the stable major release. So you can “force” the update, by switching to the beta channel, do the update and then switch back to the stable channel.
But also note, that this behavior of staged updates is intended, because sometimes, even the push of an update is paused because a bigger bug has been found in the new version. Then the next update push will start with the next point release and again mostly staged of course. So if you hadn’t the possibility to update, you were able to avoid a bad bug in this case.
See as example when NC12 came out: NC12 Updater stable release
So in general there is no reason to rush an update, but if you really want to because you want to test or try new features, you can do the mentioned trick with temporarily switching to beta channel or update manually the version via occ or even more manually by deploying the downloaded zip on the server.
EDIT: some typo