I’m in the US, and none of my edits submitted during the challenge have been decided on by the community. Keep in mind, this challenge is to get the backlog of submissions and edits down, so there’s no guarantee that anything new will be reviewed before the challenge has finished.
And yes, the challenge was announce beforehand here in the forums and other social media. This post from May 10th was the announcement that the challenge would be in 5 days.