Holy crap! I'll be an emotional wreck if all that comes to pass. I'd love to see the G be a modified / refit Galaxy Class (I was thinking Venture variant from STO).
I know it's tough, but I really gave everyone everything they want in my projection of how it ends. Really.
Remember, Worf is Klingon, not human No Klingon wants to linger on like Kor. Kor considered his longevity a curse. Worf has been ready to die on many occasions. But having him go out in a way that saves his crew and his ship is the best ending for him. He is someone who dying in his bed would be a betrayal. Also it sets up a Legacy arc for Alexander (who would be a Legacy character Matalas said) resolving his issues with his father now that he is gone.
Beverly Crusher's first identity in Encounter at Farpoint was as a mother. Picard's old friend/flame, and ship Doctor were 2 and 3. It seems only fitting then her departure allows her to do all three: have one last kiss with Picard, the true love of each others lives, then follow her son to the Delta Quadrant healing the sick... namely the sickest people of all, the Borg collective.
Data... his entire arc was about being unique. The only one of his kind on the universe. Now he knows he isn't. There is an entire planet of androids who are his Children in a sense. He gets what he wants in that, and also, hopefully, a chance to bring Lal back.
Geordi is one of the most brilliant engineers of the 24th century, but he's become a museum curator. In a way, he followed Picard into exile, without leaving Starfleet. It's time to get him back in the game.
Riker and Deanna reconciling and being on a ship again in Starfleet, specifically the Enterprise-G (or just keep it Enterprise-D in Galaxy-X form) is the only way their Season 1 arch should end, for them both to start building a life after the long morning of the passing of their son. Riker took that step first, now Deanna will join him.
And Picard, after saving the Galaxy one last time, with his family saved and future secure in Jack, it's time for him to happily retire (as opposed to Season 1) and enjoy life a little. Picard gave his entire life for Starfleet and the Federation. He's entitled now, to find happiness outside of it.
So as I said, melancholy yes, but everyone gets everything they want.