Now that I have seen the empress ending after finishing my second playthrought I'm a bit happier with the ending, While it's imo a rather sad ending at least we could spend some time with Ciri and it didn't felt that rushed like the Witcheress ending, in which we didn't even get 2 minutes of interaction with her.. It's still depressing we can't find her/Yen and Triss anywhere. I wouldn't have a problem with it if the epilogues were satisfying, but currently they are not.
I think it's pretty clear that everything after Kaer Morhen was rushed and the endings are no exception.
Looking through the leaked documents seem to proof that.
The Wild Hunt attacking Novigrad was cut.
Furthermore they changed the location of the bad ending from Kaer Morhen to Velen. The empress ending from NML to White Orchard (though White Orchard could count as a part of No men's land) and the witcheress ending from Novigrad to White Orchard. I bet they planed to show us more detailed endings, but changed them to regions they don't have to adjust that much depending on the political outcome like White Orchard.
Though that should be another proof that they had to rush the ending. I just wish they would have postponed the game for another 6 months and gave us the 3rd act this fantastic games deserves,including a satisfying conclusion of the Witcher trilogy.