Yes and no. The announcement came as the sort of surprise that makes you think in retrospect that it was actually quite predictable.
I loved the moment when that bombshell was dropped!, in fact I cheered. I thought to myself, right, he's back on course now. I really didn't like Dukat that much during seasons 3 and 4. I prefer him when he's being a bastard. It's more convincing. He doesn't do "Mr. nice guy" very well and it doesn't suit him.