Nate Silver has some pretty good commentary on it all on his X account (https://x.com/NateSilver538).

No idea. ABC bought it and slowly has been shutting down the parts of it. They got rid of the projects page, then laid off all the folks working on it after the election, and now have gotten rid of all of the articles.

Fortunately the Github is still up: https://github.com/fivethirtyeight

I'm surprised this is news - or perhaps just surprised that there was still some of 538 around ...?

ABC officially sunset 538 over a year ago (and laid off most/all of the staff).