main.qml

import QtQuick 2.7
import QtQuick.Layouts 1.1
import QtQuick.Controls 2.0

ApplicationWindow {
    id: window
    visible: true
    height: 300
    ColumnLayout{

        Button {
            text: "Push with createQmlObject"
            onClicked: {
                var qmlString = "import QtQuick 2.5;Rectangle {Component.onDestruction: console.log(\"Blue Destruction Beginning!\");color:\"blue\";}"
                var obj = Qt.createQmlObject(qmlString, stackView, "testView")
                stackView.push(obj)
            }
        }

        Button {
            text: "Push With createComponent"
            onClicked: {
                var component = Qt.createComponent("./Page1.qml")
                switch (component.status) {
                case Component.Ready:
                    //var form = component.createObject()
                    stackView.push(component) // Everithing is ok - I see "Red Destruction Beginning!"
                    break
                case Component.Error:
                    console.log(component.errorString())
                    break
                }
            }
        }

        Button {
            text: "Pop"
            onClicked: stackView.pop()
        }

        StackView {
            id: stackView
            height: 100
            width: 100
            initialItem: Rectangle {
                Component.onDestruction: console.log(
                                             "Green Destruction Beginning!")
                color: "green"
            }
        }
    }

}

Page1.qml

import QtQuick 2.5

Rectangle {
    Component.onDestruction: console.log("Red Destruction Beginning!")
    color: "red"
}