In case anyone else runs into this, sparkJ's comment is correct. You need to replace (params) with (value, row) and use row to access the value. The correct valuegetter code should be:

valueGetter: (value, row) => {
              const today = new Date();
              if (Date.parse(row.effectiveStartDateEst) > today){
                return 'Inactive'
              }
              else{
                return 'Active'
              }
            }