The only way that line applies to Endgame is if the person who sacrifices someone and the one losing that which you love don't have to be one and the same - Natasha sacrificing herself, but Clint losing her results in him getting the stone. And Gamora doesn't sacrifice herself in order to get the stone, the other way around, she wants to kill herself/sacrifice herself for Thanos not to get the stone.
(Still would have preferred it the other way around because it's IMO a misogynistic move to kill off the female character who tried everything to keep it together, to atone, and save the male character who went around 5 years killing people just because he has a family and she doesn't in the end.)