It was a passing news alert link on the jw org website which probably "expired" by design.
Those JW . org "breaking news" alerts, as was the case here, usually appear for a short time, with no dedicated archive to revisit at jw . org itself. (WT has a reputation for record archive folly)
A general internet archive may have captured evidence of the headline text before it "expired"
If you are looking to verify existence the announcement, it was also discussed at a pro-JW forum:
https://jwtalk.net/topic/52749-breaking-news-2023-conventions/
We can also expect a branch letter to be read for congregations in the near future because evidently Armageddon is not being scheduled for 2023, only more culty conventions.