I might just be a little dumb, but is there an official announcement, and/or countdown until Ethereum cannot be mined?
No and there's no ETA for that. You must keep witht the latest update about that. it seems like that if you have not even aware about that. It can be said that if the ethereum pos may get another delay again until next year. this means when you are seeing it there was a rumour about that and that's totally not true.
I can't seem to find anything definitive.
It caused by there's no exact date about that.
https://ethereum.org/en/upgrades/ please see that