The main thing I love about Nier 1 is the story, music and voice acting. I don't see how you can keep the VA as good in a remake tbh cause you can't capture lightning in a bottle twice.
The stuff that's 'bad' about old Nier is the repetitive structure, side quests and combat. Automata really only improved the combat part and even then it wasn't that good. IMO they should just remaster and bring the old game as is to new audiences rather than trying to 'fix' things that don't need fixing.
Then they should make a whole new game. Don't waste time remaking something that's already perfectly wonderful.