Didn't Epix picked it up ? And HBO would not interfere because Bute is under contract with Showtime and Froch/Hearn probably don't want to upset the TV station either. Showtime could probably sue Bute if he goes to HBO. :conf
Bute and his camp heard about the rumors of Ward swiching to HBO, he's scare he'll lose the chance to fight Ward. Showtime is scared that they would lose the mega-fight that Ward-Bute can become if he wins against Froch, and from what I've heard they're trying to force him to sign a extension of his current contract.