I think they left it open for the interpretation that Sisko could have visited Jake, Kasidy and maybe even Dax and others, in ways that are lost to time.

Jake's holorecording and his book could have all been completed before Sisko returned. Or he did return prior to those being done, but Jake left those out of the record on purpose. In either case, Sam's recreation of Jake from the record could not have been privy to what the real Jake experienced.

Perhaps Sisko even returned and finished living out a full and complete life with his family, but out of the public eye. It couldn't be recorded it would have disrupted the Bajoran religious mythos too much. I would not put it past Dax to actually know what happened, but make it a point that for the sake of history and culture and religion, that the facts be forever shrouded in mystery. Dancing around the question of Sisko's fate could be a deflection, not an admission of defeat.

"Solving the mystery isn't why we study him." "I did warn you it wasn't solvable." How would you know that for sure, Dax? Unless you're part of it?

Tawny Newsome was a guest on the Greatest Trek podcast and talked about the parallel nature of having Jake Sisko in character talking to Sam the character, but also having it be a meta conversation of Cirroc Lofton the actor taking on a kind of mentorship role to Kerrice Brooks the actor, in the way that Avery Brooks was a mentor to him on DS9. This plot is why Sam was cast as a Black woman, to make the relationship between two Black characters be more meaningful to the audience, because the show isn't just a story between two fictional space characters but also a dialogue and conversation with the Black fans watching it right now. The 'sis' thing was part of that.

If I were to extrapolate an in-universe reason, it's because Sam is developing this bond with her idea of Sisko the Emissary and how he is becoming a father figure to her, as opposed to her overbearing actual-parents The Makers, that she mentally treats Jake Sisko as the brother she never had. And so her vision of Jake addresses her as 'sis'. He does note that she's the one in control of how this whole dialogue is playing out.

I wonder how much do the Klingons know that Starfleet pulled its punches?

I thought the contrivance of involving Starfleet Academy was done very well.

From an upper decks perspective, a tragedy happened, and Starfleet was compelled to act. No need to involve the Academy, but it just so happens that the highest ranking official in Starfleet with close ties to a member of the Klingon house is the current chancellor of Starfleet Academy. (That she's 400 years old is going to be a pretty handy plot device for getting her involved in all sorts of things... but it hasn't hit the point of being annoying yet.)

Separately, it also tracks that the chancellor needs to see their only Klingon cadet privately to offer support. That's a good school administration right there. No need to involve him in the diplomatic negotiations that are going on behind the scenes.

The only reason why these converged was because of the debate class, which makes total sense that it would be a required course at the Academy, and then only because the students debated the Doctor into allowing it because they were already talking about it.

I think this would be ridiculous if it was literally every episode, but this actually worked.

Rebuilding in the wake of global disaster (and honestly it's been one after another my whole life) is exactly the kind of inspirational content I think we need right now. 90s Trek was all about "things have been great, it could be better!" and I think our message today really should be "things have sucked for a bit, but how do we recover the greatness we know we're capable of?"

I had placed a huge bet on Owo and Detmer warping the ISS Enterprise in at the last minute to save everyone's bacon, and now I'm homeless

The problem is that the Burn is space magic, but the problems of today's world is being caused by ourselves. These cadets have all the support of their political structure to enact change. We don't have that. Our entire political and economic system is stacked against us right now. You'll need to take a lot of power and money away from people who will salt the earth rather than give it up.

I love the sentiment behind it, but I can only hope it delivers on a truly revolutionary premise.

I'm kinda left wondering why it needed to be the Enterprise at all, since all we see is the ship, and no one from it. Is it just to give closure in-universe for it? Why couldn't it just be "any" mirror universe ship?

I mean, was Burnham so incurious about mirror Spock that she never checked the records?

Alright, so Stamets is outside the flow of time. Presumably he doesn't experience any of the future timelines because Stamets is dead, so do you think he just wakes up in the next time frame like it's immediate, or does he sense the gap?

Also, if it's affecting his DNA, is that a property of his body? He still has his personality in memories from before he spliced tardigrade DNA so it's not tied to the specific body itself but I thought it would have been hilarious if they went back in time and Stamets is just past Stamets.

I would have loved to see a quick shot of him waking up in a bar in San Francisco or something while Discovery was under construction just going like "wait what"

Yeah, I really thought they would do a few future jumps and have Calypso be one. It seemed that the takeaway is that regardless of how it happens, if Zora is on her own, she's at least consistent with how she spends her free time.

"Oh look, it's the AR wall" is the modern version of "oh look, it's the same octagonal set dressed up with random props from a couple of other episodes to represent an alien planet"

Identifying potentially unreliable narrators is such an underrated strategy! So a character says "The Federation has never encountered this race/phenomenon before." Off to Memory Alpha to state this as fact! But of course, people state beliefs as facts, incorrectly, all the time in real life!