chore(route53): raise awareness of sharp edges on CrossAccountZoneDelegationRecord (#33247)

### Issue # (if applicable)

N/A.

### Reason for this change

See internal tracking: P193236083

### Description of changes

Doc change only.

### Describe any new or updated permissions being added

None

### Description of how you validated changes

N/A

### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: samson-keung

packages/aws-cdk-lib/aws-route53/lib/record-set.ts

@@ -966,7 +966,11 @@ export interface CrossAccountZoneDelegationRecordProps {
 }
 
 /**
- * A Cross Account Zone Delegation record
+ * A Cross Account Zone Delegation record. This construct uses custom resource lambda that calls Route53
+ * ChangeResourceRecordSets API to upsert a NS record into the `parentHostedZone`.
+ *
+ * WARNING: The default removal policy of this resource is DESTROY, therefore, if this resource's logical ID changes or
+ * if this resource is removed from the stack, the existing NS record will be removed.
  */
 export class CrossAccountZoneDelegationRecord extends Construct {
   constructor(scope: Construct, id: string, props: CrossAccountZoneDelegationRecordProps) {