Utter bollocks. Miller was picked because he has an unbeaten record with a lot of KO's, but is actually going to walk right forward and be there to hit, to make Joshua look good. It's not like Miller is some dangerous, tricky opponent...it was not even a particularly good fight to begin with. Miller did not generate headlines any more than any other B rate fight would, and the boxing fraternity criticised it in the main.
He got a shitty ban, because boxing is a fucking joke and corrupt as fuck. Hearn is a sly one, all promoters are, but there's absolutely nothing about the Miller fight that suggests it was a set up. Ruiz Jr is actually a more skilled boxer than Miller anyway, but beating him will get far less credit from the general public so it's a lose lose.
What do you make of Wilder fighting Breazeale and Fury fighting Schwarz? All three of these bouts are poor.