The Sisko of old would have talked about this with friends or family and ask what they thought. This new Sisko is keeping it all inside and suffering in silence. In a real sense, he's actually creating the sorrow the Prophets/Wormhole aliens warned him about.
Like he did at the end of season 6?
Actually, no. As I said upthread, Sisko took a leave of absence and surrounded himself with his family (as Picard did after Wolf 359) as he sought for a way to resolve the situation presented before him at the end of season six. He didn't keep what he was doing to himself, in fact, he shared it with his family and even Dax, bringing them all into the search with him.
That's the point. It
was the easy thing to do. It's always easy to walk away from something rather than deal with it.
Sisko did retreat to his father's restaurant with his son, but he did not share what was going on with his family. Jake comments in "Image in the Sand" that Ben had not gone out or done anything in a while and hew as only sitting at the piano for long stretches. Joseph, most likely aware of Ben's depression and having experience helping him with it, suggests to Jake they just leave him alone.
Three months at a piano does not equate to solving the problem to me. It was only after his vision that he started to come out of his depression. It was after this that he started to share with Jake and Joseph what was going on and then eventually bringing Dax into it when she showed up.
In this context, DRGIII did a good job of capturing Sisko, since he isn't a character to go running to family when there's a problem, even if he is surrounded by them. This time, his family is a part of the problem and his solution is to leave them in the hopes that it keeps them safe.
I'm not in love with this version of Sisko, but I don't think it's out of character. I agree and hope to see a "getting the band back together" plot, but I'd prefer if it was like
Unity, recognizing the changes the characters have gone through, but not intent on "resetting" the characters to where they were prior to the 4-5 year gap between
The Soul Key and
Rough Beasts of Empire. I'd rather see Kira stay a Vedek, Ro stay in charge of the station, Ezri/Sam/Simon stay on the
Aventine, Worf on the
Enterprise, etc. but at least unite these characters for a reason and then send them on their ways.