I totally agree with some of the reviewers here. The finale -for me- was so disappointing.
The tone of the episode was "out of tune". .they tried to do it bitter-sweet, but for sure not funny.
As for the story itself it cancelled the whole storyline and the characters' character.
* Will and Grace were inseparable all these years and they just forgot each other because of their mates???? Wtf? In an episode they just forgot everything about their friendship. They didn't even give as a good and persuading reason why that happened.
* a child has just appeared no questions asked.
* not only Will and Grace didn't talk to each other, but they didn't even tell anything about their friendship to their children. Wtf again? The children had no idea of the existence of mum's/dad's bff for 20 years... GREAT!!
* as for Jack, he sold himself as a gigolo to an elderly gay, although he was lucky that he disappeared.
* Karen of course ended up with Jackie as a couple.. or not!
What a miss....