This is unexpected. I get a message that says the server is down for maintenance please check later. Doesn't make sense that an update 2.8.3 appears as available AND the UPDATE button is active if there is neither an update nor a server to deliver it. It's 06/2215Z and I've been checking back later every couple of hours since maybe 1600Z.
Nah... it's broke.
Nothing is "broke", of course and, the message is there precisely to indicate that.
The reason for the message is to prevent users from starting an update when it's not safe to do so (while a new one is still being uploaded), which is an obvious improvement to the previous version, where you were supposed to check the release notes and don't update until you see the updated ones.
NOW, the updater itself is taking care of that, so you are no longer supposed to know that, and you won't risk starting an update when it's not safe to do it.