Ask HN: Anyone noticed the odd timestamps on latest Windows XP patch?

Had to patch a few WinXP machines against WannCry recently, and noticed something odd.

Take a look at the XP SP3 update file - as necessary, it is digitally signed by Microsoft. Take a look at the timestamp in the signature - it's February 11th, 2017. The embedded one is 17th, the 2003 server one is 12th, Win 8th one is 13th.

That's a full month before the official update was released, on March 17th. For comparison, Win 10 one is dated March 6th. This is suspicious, even though it doesn't really prove anything - they might have known the severity of the vulnerability and prepared for it in advance or something.

But it's still suspicious - why prepare such updates beforehand, but not release them?

Am i overthinking it, or does anyone else find this odd?