To me, this rumor isn't as crazy as Screamscapes new Marvel rumor in the industrial area of his site.
For now, I'm believing in the GOTG rumor because of two simple reasons..
One, Viacom. Its a corporation thats been deteriorating these past few years; and this can very well make TWDC want to rethink in their stituation.
And two, The Twilight Zone, to agree or disagree; is not as big as it was. Its memorable, but the older it gets, it becomes more dated; to where its almost irrelevant in the public eye. Of-course, it can change if the film reboot if it comes out, is successful but that is a long shot.
Replacing the current IP makes sense but at the cost if GotG is the case, beings a big uproar in possible negative feedback. But that'd be in essance, equivalent exchange and it'd be more profitable in brand name, much more now than ever.
Take it for what you will in my thoughts.