The remaster has Nani attend University, leaving Lilo in the care of their neighbor whose known their family forever, Tūtū. She also has an alien teleporter that allows her to visit Lilo frequently.
The film seems to choose to use some fairly hand-wavy solutions at the end so that they don't have to compromise the happy ending with bittersweetness.
Like, I don't think anyone would say Nani made the wrong choice by fighting hard and making sacrifices to hang onto her little sister in the original film, even though that holds its own sad implications.
I also think that the backlash over this new script is fairly justified, since it completely erases all the consequences that any real person in Nani's situation would face for making the same decision. There will be feelings of abandonment if you surrender your position as primary caregiver, even when it's the right choice. The movie goes out of its way a bit to have its cake and eat it too.
You can't fool me. If a sink was at my door, it'd knock.