A book is not a newspaper or a magazine, and a book that's compiled as an oral history should not be filed under "current events".
This is obviously written for posterity, and not for only the year 2021.
What's funny is that I take that point, but see it the other way. A book that is trying to chronical a history of a theatre might well note that production was interrrupeted for over a year due to a pandemic - something that readers in the future might want clarified.
she could've turned in final proofs of the book last summer when people (including the Broadway League) were still speculating/hoping theatre would come back in early 2021.
You're faulting her for prognostication skills
I'm assuming that the text still could have been corrected.
In any case, pecansforall asked us if we could find the "glaring error" in the quoted excerpt, and for me, to say a show is "still running" when it isn't is indeed a glaring error.
But hey, only on ATC would this observation become a national crisis, lol.