Prepare statement should not inline query parameters

CREATE INDEX ix1 ON default(type);

INSERT INTO default VALUES ("f001",{"type":"rule", "ruleVersions":[{"maxDischargeDate":"2017-01-01", "state":100,"groupTags":["tag1"]}]});

\set -$groupTags ["tag1"];

\set -$dischargeDate "2016-10-21T00:00:00";

PREPARE p1 FROM SELECT  maxAppVer.theRule

FROM default rules

LET maxAppVer = (SELECT MAX(maxRule.version) AS ver, maxRule AS theRule

                 FROM rules.ruleVersions as maxRule

                 LET minApp =  (SELECT MIN(minRule.maxDischargeDate) AS minDate

                                FROM rules.ruleVersions AS minRule

                                WHERE minRule.maxDischargeDate >= $dischargeDate AND

                                      minRule.state IN [100]) [0]

                 WHERE maxRule.maxDischargeDate = minApp.minDate AND

                       maxRule.state IN [100] AND

                       ARRAY_LENGTH(ARRAY_INTERSECT($groupTags, maxRule.groupTags)) > 0

                 GROUP BY maxRule)[0]

WHERE rules.type = "rule" AND maxAppVer IS NOT MISSING ;

select meta().plan, * from system:prepareds;

The plan prepareds cache looks fine

EXECUTE p1;  

-- should return 1 row

select meta().plan, * from system:prepareds;

Prepareds cache plan is replaced $dischargeDate with actual value. which is in correct

\set -$dischargeDate "2017-10-21T00:00:00";

EXECUTE p1;  

-- Should return 0 row but returns 1 row

\set -$dischargeDate "2016-10-21T00:00:00";

 EXECUTE p1;  

-- should return 1 row

{

                                                "#operator": "Let",

                                                "bindings": [

                                                    {

                                                        "expr": "(correlated (select max((`maxRule`.`version`)) as `ver`, `maxRule` as `theRule` from (`rules`.`ruleVersions`) as `maxRule` let `minApp` = (correlated (select min((`minRule`.`maxDischargeDate`)) as `minDate` from (`rules`.`ruleVersions`) as `minRule` where ((\"2016-10-21T00:00:00\" <= (`minRule`.`maxDischargeDate`)) and ((`minRule`.`state`) in [100])))[0]) where ((((`maxRule`.`maxDischargeDate`) = (`minApp`.`minDate`)) and ((`maxRule`.`state`) in [100])) and (0 < array_length(array_intersect($groupTags, (`maxRule`.`groupTags`)))))  group by `maxRule`)[0])",

                                                        "var": "maxAppVer"

                                                    }

                                                ]

                                            },