A sarcastic phrase said in response to outdated news. It is used humorously or ironically to suggest that a piece of supposed ‘news’ is in fact stale, or more broadly that a person who says something is simply stating the obvious or restating a well-worn or accepted truth.
The expression is first recorded in 1798 , by which time Queen Anne had indeed been dead for 84 years.
Example
A – Do you know Covid – 19 is a pandemic?
B – Oh really? Did you know Queen Anne is dead?