exempt school buses and emergency vehicles.

I don’t think it ever applied to emergency vehicles, although I’m not sure about school buses.

Indeed:

Qualifying authorized emergency vehicles, qualifying vehicles transporting a person with disabilities, specialized government vehicles, and transit and commuter buses would be exempted from the CBD toll

• https://abc7ny.com/nyc-congestion-pricing-plan-start-date-tolls-exemptions/14726774/, from the original plan

I’m not sure if commuter buses include school buses, but you’d expect it too.

The main changes seem to be a reduction in tolls. Which is fine as a starting point, although I hope they increase relatively quickly.