I can't confirm that and there are official documents saying Delavan - for example this 1955 map from the city https://nycdcp-dcm-alteration-maps.nyc3.digitaloceanspaces.com/cp12156.pdf

As well as this 1946 map: https://nycdcp-dcm-alteration-maps.nyc3.digitaloceanspaces.com/cp4276.pdf

As well as the NYC Street Map https://streets.planning.nyc.gov/about?lat=40.68&layer-groups=%5B%22amendments%22%2C%22citymap%22%2C%22pierhead-bulkhead-lines%22%2C%22street-centerlines%22%5D&lng=-74.0075&zoom=17.29

The Citibike station is also called "Richards St & Delavan St". It's true that parcels on Regrid say Delevan, but with all of the street signs as well as the official street maps saying Delavan, I think that's the predominant spelling on the ground.