They relegated Tenchi Muyo GXP to 3 AM because they sorely misjudged what kind of show it was and it got poor ratings. They allowed it to finish, but they never reran it.
The HD remastered tapes of Cowboy Bebop only played on Toonami for 4 episodes before the block was cut in half, and then so far, never again.
I'm not sure how frequent they kept taking shows off before they finished in the past though. In this case, the OP anime won't end for a long time! So OP being taken off Toonami before they caught up to the dub was always extremely high.