OPM has the same problem as MHA, it's so popular that every anime fan and their dog has seen it multiple times, then seen 500 memes and 20 reaction videos about it.
I think Toonami is still struggling with the fact that the Inuyasha days are over... the days where you could run the same episodes of old anime dozens of times and still draw ratings.
Remember when they tried rerunning Jack at the top of the lineup? And AOT? They think old stuff and reruns will still draw, they don't.