To expand on what Robert said (because, hey, I have lots of time on my hands)..."Birthright" is a story about both Data and Worf learning about their fathers. The story started on Deep Space Nine in the first part and included a guest shot from Doctor Bashir. His role helped Data to access "dreams" and to connect with Dr. Soong. There's no real need for Sisko to show up, or any of the other regularsI am partial to episodes that take place on the Holodecks across the franchise. The Big goodbye, Elementary dear Data, Ship in a bottle etc. I am a big fan of the 7th season of DS 9 with Vic Fontaine in 1960s Las Vegas
However, I’m also confused. When DS 9 Premiered, Picard came to the station to discuss the Bajor situation. He tells Sisko that Preparing Bajor for Federation membership is his responsibility.
But in TNG Birthright, Sisko doesn’t appear
It's almost like why did Quark show up in Voyager's "Caretaker" instead of Sisko? Because there was no logical way to put him in the episode. (Plus, Quark is arguably more popular AND the prior spinoff pilot-DS9's "Emissary"-had already included the lead from the prior show and doing the same thing again would have been pretty redundant.)
Overall, Sisko's mission from Day One, as stated, as to get Bajor ready to join the Federation. And that is what Sisko did: protected Bajor and did what he could to get them ready.