Are you sure about that? Unless I'm misunderstanding they did fix this: https://pkg.go.dev/encoding/json

"In v1, a nil Go slice or Go map is marshaled as a JSON null. In contrast, v2 marshals a nil Go slice or Go map as an empty JSON array or JSON object, respectively. The jsonv2.FormatNilSliceAsNull and jsonv2.FormatNilMapAsNull options control this behavior difference. To explicitly specify a Go struct field to use a particular representation for nil, either the `format:emitempty` or `format:emitnull` field option can be specified. Field-specified options take precedence over caller-specified options."