What if this actually is the end of edo Itachi? He used tsukyomi on Sasuke. Some wondered why, and I thought it was just a random genjutsu Itachi used, that it didn't really matter which genjutsu he used to break free.
But, Itachi probably already spoke to Sasuke during that Tsukyomi. It lasts for three days, long enough for them to have a proper goodbye.