Gunn seems to think that this one change makes the story work better for everyone, and it’s hard not to see his point.
She has had her own parental problems but really tried to make it work for her teammate.
The green-skinned badass has daddy issues of her own (in case you’ve been living under a rock, her dad is Thanos), and her willingness to extend an olive branch and bridge the gap between Star-Lord and Ego (whether intentional or not) seems to show where she mentally is during the events of Vol. 2.
Aside from helping make the dynamic between Ego and Peter Quill more compelling, the change also helped to deepen Gamora’s character in ways not necessarily seen during the events of the first Guardians of the Galaxy movie.