When exactly did the Blood Trolls slaughter the followers of Krag’wa?
Zentimo is described as his last follower before he dies, implying it happened pretty recently. But on the other hand, some people in Zuldazar are surprised to hear that Krag’wa is back, and THAT implies he’s been out of commission for a while.
Krag’wa has been around for a long time and he hasn’t been missing. He had many followers until he refused G’huun and all of them got killed immediately before the questing.
I’m not sure what people in Zuldazar you are talking about, but maybe they are surprised he’s taking an active role personally defending the capital?