In this thread someone says that Sony will not accept that Fictionwise can not publish in Sony's format. We still have to wait for development on this.
https://www.mobileread.com/forums/showthread.php?t=8597
Is this really legally possible? What if someone wanted to translate it, can they refuse to sell them the rights?
To me, besides the DRM issue, that really looks like shooting oneself in the foot!