they said that "Legal issues" are what caused them to have to postpone it
and unless the show itself is being sued for plagiarism, or the show's content itself being somehow illegal in the U.S. there's ONLY ONE OTHER "legal issue" that I can imagine would delay a show's airing
a write off, CN and AS have written off several shows from the Stuart Snyder Era and shotly before, BUT have previously reversed a write off for a show Prior to bring it to Toonami, that show being IGPX
so due to that, there is a small handfull of of written off Anime-type series that I know of CN having written off that could very well be the show Toonami postponed with Space Dandy
Symbionic Titan: was written off right after Toonami's second reairing basically without their consent
Megas XLR: was also written off and the creator left CN for Disney to develop a spiritual Remake (which was also later written off)
Thundercats 2011: the possibility that Toonami wants this show....would make sense....since it was meant to be an adult show to begin with