As I mentioned in a prior post on this thread, IMO the girls' pre-1917 diaries were likely packed in crates in the outside storage sheds, as Nicholas and Alexandra's were. They probably only burned what was immediately at hand: the 1917 & 1918 volumes.
That makes total sense. So as far as we know none of the post-1916 diaries of the two girls survived?
Correct -- provided Royal Sisters of Mercy reported GARF's holdings accurately.
The blank book Tatiana used for her 1916 diary ends in late fall or early winter. (The latest entry printed in RSM is 24 October 1916.) Presumably she began a fresh one in late 1916 which would have continued into 1917, but no such diary is known to exist -- perhaps because she destroyed it at some point.
I know Olga's diary stops abruptly on 15 March 1917, but there's one thing that's not clear to me: did she simply stop making entries after the revolution, or were the post-revolutionary pages removed from the diary?