User blog comment:AnimeMegaFan30/Only 6 more Episodes of Inuyasha: The Final Act left to go.../@comment-7866392-20150503072723

If Toonami still had a 6-hour lineup, I could see them rerunning The Final Act at 5:30 AM, since the original InuYasha did so well at that slot (well, at least it did when it was airing encores during both slots of the 5:00 AM hour).

They'll most likely replace it with a new show, since the 3:00 AM "rerun" slot is currently occupied by Attack on Titan. Personally hoping for either Sailor Moon Crystal, Tiger & Bunny, or Coppelion.

On the possibility of them deciding to bring back a previously-aired show, I'm keeping my fingers crossed for either Samurai 7 or Black Lagoon.