The SpaceAroundOperator flags violations for a?[b]
There is already an explicit exception for the array operator [ at https://github.com/CodeNarc/CodeNarc/blob/master/src/main/groovy/org/codenarc/rule/formatting/SpaceAroundOperatorRule.groovy#L167

I am using version 3.3.0-groovy-4.0 for testing