The "gerrymandered" zoning is tough to defend.
On the other hand, the area should be properly upzoned.
Upzone? Not clear. Schools are overcrowded in the area. Permitted density levels already are pretty high for a largely residential area. It's not and probably shouldn't be like Midtown. In any case getting an upzoning through this neighborhood probably is impossible.
Schools are an easy problem to solve: require buildings of a certain size to include a school. It's been done before in NYC.
Sadly you're entirely correct that NIMBYs would fight it tooth and nail, and have the money+connections to succeed.
You're right about schools. Those originally objecting to this project often said that any new building in the area of this size should provide school space or construction subsidies. And that makes sense both for the UWS and any other similar area. There are tons of kids living around 200 Amsterdam including in my building and PS 199 can't handle the load.