They said Bianchi's story left breadcrumbs about how a guy could come back. The Romulus storyline was awful right? It was just an excuse to remove all of Wolvie's popular foes-sabes, Omega Red, etc.
Either way, I usually enjoy Sabertooth decimating wolverine to remind writers that wolverine isn't an alpha, just a dog.
"Jeph Loeb and Simone Bianchi will reteam on "Wolverine" to bring back the arch-villain they killed off a few years back as Sabertooth is on the prowl again. "I appreciate everybody who stood on the wall at Marvel and said 'No, he's not coming back,'" Loeb said of Marvel keeping the character off the table for other writers so he could do this story. He added "I've said in other interviews that the story we told was not the whole story...if you've been clamoring for Sabertooth to return and make Wolverine's life miserable [this is the place]." He added that if fans go back and read he and Bianchi's last Sabertooth story, the breadcrumbs that can explain how he can return after being decapitated are all in there."