Ok, I'll spell out what I meant. One of the possible scenarios where, centuries after GAI was created, there would still be humans (recognizable to us as such) alive, is the same as the reason why horses and pigs and cows are alive today - because they're bred as inputs to some industrial process.
Well, in human history there have been many people bred as inputs to an industrial process. Today most people of conscience look on those situations (past and present) in horror. I would hope that humans someday learn to never allow that to happen to any of us again.
Dude, already happening, it never stopped, it isn't 'horror' it's 'efficiency'. There is no such thing as 'people of conscience'. It will always happen, because, human nature.
Alright there will always be some that stubbornly cling on, but I would bet that most entities that could be considered intelligent beings won't be human by that point, just out of practicality.
Stupid flesh and blood humans with their finite needs! Let's build cyborgs with infinite information processing capability so their needs can never be saturated!
I will go on the record and predict there will be some human beings alive in a few hundred years.