Why is my iPhone claiming "a change to iCloud Keychain servers"?

I'm getting this too. I don't trust it becasue of the missing Support Article. Can anyone confirm this change?

I got it tonight. I do think it is suspicious - but it does take you through the normal settings screen for icloud. Can't find anythng about it when I google it. I might call Apple.

I did contact Apple support (via chat) - and they indicated that there are a number of circumstances which can trigger that notification - specifically if you have reformatted the drive on Mac on your network. It was a little bit vague. In any case - I have reformatted and reloaded of my Macs several times doing a clean install of mavericks as well as restoring the image of mountain lion - and additionally re-adding my icloud account to the reloaded Mac a number of times. I also did a RAM upgrade tongiht on that same Mac just a few hours prior to receiving the notification to change my iCloud keychain security code. It is very possible that I changed too many things and maybe as a safeguard it wanted me to change my icloud security code. They are forward this information to Apple enginneers to possibly get the broken link on the notification corrected as well as making the wording of the message more clear. I am going to change my apple id passwords and security code - via the normal channel - just to be safe. Sorry that this was not more definitive - but Apple is not forcing people to change their keychain security codes because of a change in Apples iCloud servers.

~Scott

Some additional supporting information. Right before this happened - I was listening to a streaming radio station - via an app called iHeart Radio - which had been working fine. It wanted to log in via Facebook - and it appears that my wifi connection dropped (very unusual for that to happen) at the time it was attempting to use the (iCloud) keychain to access facebook. I'm wondering if the dropped wifi right at that time maybe confused the keychain - because the change icloud keychain notification popped up shortly after reconnecting to wifi. Another question might be is whether the App on the iPad (the iHeart Radio app) attempted to improperly (and not necessariy maliciously) attempted to access the keychain - causing the request to change the passcode. Just a guess - with no substantiating evidence.